Yemeni rebels killed their erstwhile ally Ali Abdullah Saleh, the country’s former president and strongman, as their forces battled for control of the capital, Sanaa, officials said. The collapse of their alliance throws Yemen’s nearly 3-year-old civil war into unpredictable new chaos.

The circumstances of Saleh’s death were unclear but Houthi officials said their forces caught up with him as he tried to flee Sanaa.

A video circulating online purported to show Saleh’s body, his eyes open but glassy, motionless with a gaping head wound, as he was being carried in a blanket by rebel fighters chanting “God is great” who then dump him into a pickup truck. Blood stained his shirt under a dark suit.

It was a grisly end for a figure who was able to rule the impoverished and unstable country for more than three decades and remained a powerhouse even after he was ousted in a 2011 Arab Spring uprising. His death recalled another Arab leader killed in the midst of his own country’s uprising, Libyan leader Moammar Gadhafi, whose body was shown in a video being abused by rebels who killed in him 2011.

Saleh’s death was announced by the rebels, known as Houthis, who have been fighting Saleh’s forces for the past week. Two of Saleh’s associates have confirmed and a third official from the government of Yemen’s internationally recongnized president, Abed Rabbo Mansour Hadi, has also confirmed.

“The leader of treason has been killed,” Houthis’ TV network al-Masriah said.

Saleh allied with the Houthis, and the support of his loyalist military units was key to helping the Houthis overrun the capital, Sanaa, in 2014, driving out Hadi’s government. But in recent months, the alliance frayed amid Houthi suspicions Saleh was leaning toward the Saudi-led coalition backing Hadi.

Hadi’s forces, trying to take advantage of the collapse of the alliance, announced they would march on Sanaa.

But even without Saleh’s loyalists, the rebels remain a powerful force and it is unclear how much the break with Saleh weakens them. Over the past year, the Houthis had steadily undermined Saleh and reduced their need for him, winning military commanders over to their side and boosting their own forces.

A major question now will be whether Saleh’s loyalists — and tribes that support him — can rally to fight the Houthis after his death.

Several Houthi military officials said Saleh was killed as he headed along with top party leaders from Sanaa to his hometown of Sanhan, nearby. Houthi fighters followed him in 20 armored vehicles, attacked and killed him and almost all those with him, the officials said, speaking on condition of anonymity because they were not authorized to talk to the press. A Houthi media official, Abdel-Rahman al-Ahnomi told the Associated Press that Houthi fighters killed Saleh as he tried to flee to Saudi Arabia though the province of Marib, to the east of the capital.

The Saudi-led coalition had hoped that Saleh’s break with the Houthis would be a turning point, isolating the rebels. Over the past days, fighter jets from the Saudi-led coalition pounded Houthis positions, throwing support behind Saleh and fueling divisions with Houthis. Hadi’s government had expressed willingness to turn “a new page” with whoever stands against the rebels.

The fighting left Sanaa divided. The Houthis dominate the northern part of the city, while Saleh’s forces hold the southern part, with much of the current fighting concentrated around the Political District, home to ministries and foreign embassies. The Houthis appeared to be targeting the homes of Saleh’s family, political allies and commanders.

Civilians living in the area are largely cut off from the outside world.

Yemenis huddled in basements across Sanaa overnight as airstrikes echoed across the city. Suze van Meegen, Sanaa-based protection and advocacy adviser for the Norwegian Refugee Council, said the violence left aid workers trapped inside their homes and was “completely paralyzing humanitarian operations.”

“No one is safe in Sana’a at the moment. I can hear heavy shelling outside now and know it is too imprecise and too pervasive to guarantee that any of us are safe,” she said.

“The night was tough,” Robert Mardini, the regional director of the International Committee of the Red Cross, posted on his Twitter account. “Massive urban clashes with heavy artillery and airstrikes. Yemenis stuck in their homes, too scared to go out. Reduced access to water, health care, food and fuel.”

In southern Sanaa’s Fag Attan neighborhood, the Houthis used tanks, artillery, and anti-aircraft guns to try to take out snipers loyal to Saleh, damaging or destroying several buildings.

Residents said the night was shattered by the sounds of gunfire and children screaming.

“It’s like horror movies,” said Bushra, a local woman who asked that her last name not be published for fear of retribution. “I have lived through many wars but nothing like this.”

Witnesses said the bodies of slain civilians and fighters littered the streets, as no ambulances were able to reach the area. The ICRC says at least 125 people have been killed and some 240 wounded in Sanaa since the fighting began Wednesday.

Jamie McGoldrick, of the U.N. Office for the Coordination of Humanitarian Affairs, described the fighting in Sanaa as “another dark chapter of life here.” Speaking from Sanaa, McGoldrick said that humanitarian agencies are close to the front lines and that aid workers are also sheltering in basements. He called for a humanitarian pause to the fighting to allow civilians to escape.

During his more than 30 years in power, Saleh was known as the man who “dances on the heads of snakes” for his mastery of shifting alliances, playing both sides or flipping sides in the multiple conflicts tearing apart Yemen.

In the 2000s, he was a key ally of the U.S. in the fight against al-Qaida, taking millions of dollars in American aid to hunt down the group’s branch — even as he was accused of striking alliances with the militants and using them against his own enemies. During his rule, he fought multiple wars against the Houthis in northern Yemen, only to side with them against his own former vice president-turned-successor, Hadi, after he lost power.