DAMASCUS, Syria — Ousted Syrian leader Bashar Assad fled to Moscow and received asylum from his longtime ally, Russian media said Sunday, hours after a stunning rebel advance seized control of Damascus and ended his family’s 50 years of iron rule.

Thousands of Syrians poured into streets echoing with celebratory gunfire and waved the revolutionary flag in scenes that recalled the early days of the Arab Spring uprising, before a brutal crackdown and the rise of an insurgency plunged the country into a nearly 14-year civil war.

The swiftly moving events raised questions about the future of the country and the wider region.

“Our approach has shifted the balance of power in the Middle East,” President Joe Biden said, crediting action by the U.S. and its allies for weakening Syria’s backers — Russia, Iran and Hezbollah. He called the fall of Assad a “fundamental act of justice” but also a “moment of risk and uncertainty,” and said rebel groups are “saying the right things now” but the U.S. would assess their actions.

Russia requested an emergency session of the U.N. Security Council to discuss Syria, according to Dmitry Polyansky, its deputy ambassador to the U.N., in a post on Telegram.

The arrival of Assad and his family in Moscow was reported by Russian agencies Tass and RIA, citing an unidentified source at the Kremlin. A spokesman there didn’t immediately respond to questions. RIA also said Syrian insurgents had guaranteed the security of Russian military bases and diplomatic posts in Syria.

Assad Wants Peaceful Transfer of Power: Russia

Earlier, Russia said Assad left Syria after negotiations with rebel groups and that he had given instructions to transfer power peacefully.

The leader of Syria’s biggest rebel faction, Abu Mohammed al-Golani, is poised to chart the country’s future. The former al-Qaida commander cut ties with the group years ago and says he embraces pluralism and religious tolerance. His Hayat Tahrir al-Sham group, or HTS, is considered a terrorist organization by the U.S. and the U.N.

In his first public appearance since fighters entered the Damascus suburbs Saturday, al-Golani visited the Umayyad Mosque and described Assad’s fall as “a victory to the Islamic nation.” Calling himself by his given name, Ahmad al-Sharaa, and not his nom de guerre, he said Assad had made Syria “a farm for Iran’s greed.”

The rebels face the daunting task of healing bitter divisions in a country ravaged by war and split among armed factions. Turkey-backed opposition fighters are battling U.S.-allied Kurdish forces in the north, and the Islamic State group is still active in remote areas.

Syrian state television broadcast a rebel statement saying Assad had been overthrown and all prisoners had been released. They urged people to preserve the institutions of “the free Syrian state,” and announced a curfew in Damascus from 4 p.m. to 5 a.m.

An online video purported to show rebels freeing dozens of women at the notorious Saydnaya prison, where rights groups say thousands were tortured and killed. At least one small child was seen among them.

“This happiness will not be completed until I can see my son out of prison and know where is he,” said one relative, Bassam Masr. “I have been searching for him for two hours. He has been detained for 13 years.”

Rebel commander Anas Salkhadi appeared on state TV and sought to reassure religious and ethnic minorities, saying: “Syria is for everyone, no exceptions. Syria is for Druze, Sunnis, Alawites, and all sects.”

“We will not deal with people the way the Assad family did,” he added.

Celebrations in the Capital

Damascus residents prayed in mosques and celebrated in squares, calling, “God is great.” People chanted anti-Assad slogans and honked car horns. Teenage boys picked up weapons apparently discarded by security forces and fired into the air.

Soldiers and police fled their posts and looters broke into the Defense Ministry. Families wandered the presidential palace, walking by damaged portraits of Assad. Other parts of the capital were empty and shops were closed.

“It’s like a dream. I need someone to wake me up,” said opposition fighter Abu Laith, adding the rebels were welcomed in Damascus with “love.”

Rebels stood guard at the Justice Ministry, where Judge Khitam Haddad said he and colleagues were protecting documents. Outside, residents sought information about relatives who disappeared under Assad.

The rebels “have felt the pain of the people,” said one woman, giving only her first name, Heba. She worried about possible revenge killings by the rebels, many of whom appeared to be underage.

Syria’s historically pro-government newspaper al-Watan called it “a new page for Syria. We thank God for not shedding more blood.” It added that media workers should not be blamed for publishing past government statements ordered from above.

A statement from the Alawite sect that formed the core of Assad’s base called on young Syrians to be “calm, rational and prudent and not to be dragged into what tears apart the unity of our country.”