Sana, Yemen — Violence convulsed the streets of Yemen’s capital for a second straight day on Monday as government security forces battled soldiers who have joined anti-government protesters in the worst violence since March.
Medical officials in the capital said at least 19 people had been killed on Monday, pushing the death toll from two days of fighting in Sana, the capital, to more than 40.
Motorcycles and ambulances carried mangled bodies away from the center of fighting, an intersection just south of an area where protesters have been holding sit-ins for months.
After sporadic gunfire overnight, fighting intensified on Monday as rocket-propelled grenades fell near the protesters, and forces loyal to Maj. Gen. Ali Mohsin al-Ahmar fired artillery at positions held by government forces nearby. At least one residential building near the protest was in flames.
Soldiers from the First Armored Division, commanded by General Ahmar and fighting on the side of the protesters, had taken over the area Sunday evening after clashing with security forces. Protesters set up tents in the major intersection, known as Kentucky Square, which has become the new frontline of fighting.
The area is close to a residence of President Ali Abdullah Saleh’s family, in the direction of the presidential palace.
Despite the renewed battles near the heart of the main antigovernment demonstration, protesters remained on Monday.
“We are staying here until we die,” said Wuheib al-Youseffy, 32, sitting on a curb with a group of men amid gunfire and booming artillery explosions. “Why should we be scared? We are used to this.”
The bloodied bodies of protesters could be seen sprawled on the floor in videos posted on Monday by activists in Sana’s central square. Many appeared to be dead, including a young boy who activists said was killed by sniper fire.
South of the capital, fighting flared in the city of Taiz, according to news reports, with at least one protester killed and more than a dozen wounded as demonstrators battled government forces.
Yemen’s divided military has been at a standoff on the streets of Sana for months, but after an attack Sunday on protesters, the First Armored Division fought back.
A United Nations envoy, Jamal Benomar, was set to arrive in Sana on Monday to oversee negotiations between the vice president and leaders of opposition political parties about the possible transfer of presidential powers.
But it was unclear whether such an agreement, even if it were struck, would stop the latest fighting. The clashes began in Sana on Sunday when security forces firing from rooftops and from the back of pickup trucks turned heavy-caliber machine guns and other weapons on demonstrators , setting off battles between army defectors and forces loyal to the government.
Sunday’s violence left at least 24 demonstrators dead and more than 200 wounded in the Yemeni capital and threatened to scuttle any hopes for an accord between President Saleh and his opponents, who have been locked in a standoff for months over demands that he step down and transfer power. The fighting also raised the prospect of open and more intense sparring among factions of Yemen’s divided military, which many here fear could lead to civil war.
On Monday, many protesters in Sana were comparing their situation to the fighting in Libya, where antigovernment forces supported by a NATO bombing campaign ended the rule of Col. Muammar el-Qaddafi.
“The international community isn’t doing anything here,” said one protester Awad Mansour, 26. “Look at Libya: they froze their assets, they helped the rebels, and for us, they don’t do anything.” Others said they believed the antigovernment movement, which has remained peaceful, would have to become violent in order to finally remove President Saleh.
Already the political paralysis has sapped the weak central government in a country whose untamed reaches have become a base for Islamist militants linked to Al Qaeda. Conflict has raged in outlying provinces for months. The vacuum of authority has concerned American officials, who have struck at the Qaeda cells with drone aircraft run by the Central Intelligence Agency.
Mr. Saleh himself remains out of the country, in Saudi Arabia, where he has been recuperating from wounds suffered in a bomb attack on the presidential palace in June.
The violence on Sunday began as the antigovernment demonstrators tried to march for the first time in months beyond the part of Sana where they have camped in a sit-in under the protection of General Ahmar As they did, men in civilian clothes opened fire from rooftops, the protesters said, and government security forces shot at them from a Ministry of Electricity building and, using machine guns, from the backs of pickup trucks. The gunfire lasted about an hour.
A separate group of protesters marching on what is known as the Ring Road, which runs around the capital, were met with gunfire and tear gas as soon as they left the area controlled by the First Armored Division, an attack that continued into the evening.
“I swear to God what happened today is a horrible massacre, and we are not able to even describe it, that the regime would use this violence against peaceful protesters,” said Bassem al-Sharjabi, a lawyer who is one of the protest leaders. “This is a crime against humanity. We demand from the international community to intervene to stop these crimes.”
Protesters said that the army division that opened fire on them with heavy weapons was under the command of Gen. Yahya Saleh, nephew of the president and chief of central security forces.
Yemen’s government issued several online statements on Sunday accusing the protesters of staging an illegal march and saying that members of the Islamist political party started the attacks.
General Saleh denied that his soldiers used ammunition of any sort on the demonstrators. Rather, he said, the fight was started between neighborhood residents and the protesters themselves.
“What happened today, we used tear gas only and water cannon only,” General Saleh said in a telephone interview. “And the shooting is between local citizens of the area, the first armored brigade who occupy Sana University and some of the people who were inside the demonstration. They were all shooting at each other.”
The attack on the protesters reflected the recent spike in tensions between President Saleh’s security forces and the tribesmen loyal to his main rivals, the Ahmar family, who are not related to General Ahmar.
Last week explosions rocked the capital, and the tribesmen loyal to the Ahmar family resumed fighting with the president’s forces. There were fears that the latest attack on the protesters would lead to more such violence. Explosions and gunfire echoed across Sana into the night on Sunday, though it was not clear where they were occurring.
Sakher al-Oldany, a 20-year-old protester, said the marchers moved beyond the area protected by the First Armored Division because they “wanted to escalate” the rebellion against the government. He and others said the violence would not deter them from continuing their protests.
Mr. Oldany was being treated at a mosque in the sit-in area, next to Sana University, that has been turned into a makeshift hospital. Inside, bodies were scattered everywhere, and blood stained the floors. A doctor, Abdel-Wahab al-Anesi, provided the tally of dead and wounded.
The hospital was more organized than it was during fighting last spring, but the doctors and nurses who volunteer their time there did not plan for the number of wounded on Sunday, and dozens of people who had been shot were lying on the floor.
Wounded men talked on their cellphones, calling their wives to tell them they were alive.
At one point, the power went out when the generator stopped working, a reminder of the hardships that Yemenis face.
Doctors scrambled to treat the wounded and load the most serious cases into an ambulance to be taken to a nearby hospital. Other ambulances and motorcycles zoomed through the tent-lined streets of the protest area to gather the wounded.
“This regime doesn’t respect anyone,” said Bilquis Mohammed, whose 17-year-old son was shot in the leg. “We want all those responsible for this to be tried and put before courts. All our children are in there.”
The sit-in has woven itself into the fabric of the city. Protesters normally stay within its boundaries or, at the most, stage marches within the territory controlled by General Ahmar, who announced his support for the protesters in March after more than 52 demonstrators were killed by snipers linked to the government.
General Ahmar’s defection tore apart the Yemeni government, and negotiations began days later in an effort to force Mr. Saleh to give up power, but the president has repeatedly refused to sign any agreement.
It was unclear how the violence on Sunday would affect the delicate political balance in Yemen.
President Saleh recently issued a decree authorizing his deputy to negotiate and sign a transfer-of-power agreement, a move that could lead to early presidential elections.
But one former Yemeni official, Jamila Raja, said that chances were now slim.
“I think it’s aborting all the efforts for reconciliation and to continue on with the dialogue,” said Ms. Raja, an adviser to the Foreign Ministry who resigned last spring over the violence used against the protesters.
Another official, Yemen’s ambassador to Spain, Mustapha Noman, said that the violence was a deliberate attempt to wreck any plans for a peaceful transfer of power.
“There are forces trying to sabotage all the attempts to reach a peaceful end to the miseries Yemen is witnessing for the past eight months,” he said.
This article, "Fighting Erupts for Second Day in Yemeni Capital," originally appeared at The New York Times.