Syrian President Ahmad al-Sharaa urged Alawite insurgents in the northwest of the country to surrender "before it is too late" on Friday evening, as more than 300 Alawite civilians have been executed in the region, according to an NGO.

"You have attacked all Syrians and committed an unforgivable mistake. The response has fallen, and you could not withstand it. Lay down your arms and surrender before it is too late," said the interim Syrian president, who led the Islamist coalition that overthrew Bashar al-Assad on Dec. 8.

"We will continue to work toward a monopoly of arms in the hands of the state, and there will be no more uncontrolled weapons," he added in a speech broadcast on the Syrian presidency’s Telegram channel.

This brings the death toll from the clashes since Thursday to more than 300 Alawite civilians killed by Syrian security forces and allied groups in sweeping operations and clashes with Assad loyalists in the west of the country. The NGO reported "the death of 311 Alawite civilians in the coastal region (…) killed by security forces and allied groups."

"The vast majority of the victims were summarily executed by elements affiliated with the Ministries of Defense and Interior," the NGO added Friday. These deaths bring the overall toll from the clashes since Thursday to 524, including 213 members of the security forces and allied groups, according to the same source.

Clashes in Assad strongholds

After several days of clashes in the Latakia and Tartous regions — bastions of the Alawite minority to which the deposed president belongs — the violence escalated when Assad loyalists launched a bloody attack against security forces in the coastal town of Jableh on Thursday night, according to authorities.

Security forces sent reinforcements Friday and launched sweeping operations in the region, particularly in Qardaha, the Assad clan’s stronghold. A curfew was declared until Saturday in Latakia and Tartous.

Restoring security in the country is the main challenge for the new government, formed by an alliance of Islamist rebel groups that overthrew Assad after more than 13 years of civil war.

‘Everyone is afraid’

"People are staying indoors. Everyone is afraid," said Ali, a Jableh resident, contacted by AFP from Damascus.

The Syrian Observatory for Human Rights and activists have published videos showing dozens of bodies in civilian clothes piled up in the courtyard of a house, with women crying nearby. In another video, men in military uniform order three people to crawl in a row before shooting them at point-blank range.

AFP could not independently verify these videos.

Meanwhile, a security source quoted by the official Syrian agency SANA reported "isolated abuses" committed by "unorganized mobs" in retaliation for "the assassination of several members of the police and security forces by men loyal to the former regime."

"We are working to put an end to these abuses, which do not represent the entire Syrian people," added the source from the Interior Ministry.

Aron Lund, of the Century International think tank, described the situation as a "ticking time bomb."

"Both sides feel targeted, both sides have suffered horrific abuses at the hands of the other, and both sides are armed," he told AFP.

On Thursday night, while gatherings took place in several cities in support of the authorities, messages broadcast from mosque loudspeakers called for "jihad" (holy war), according to the Syrian Observatory for Human Rights.

The Kurdish self-administration that controls much of northeastern Syria called on "all involved political forces to engage in a national dialogue" for "a comprehensive political solution."

U.N. special envoy for Syria Geir Pedersen said he is "deeply alarmed" and called on all parties for "restraint."

Moscow, where Assad fled, urged Syrian leaders to "de-escalate" to "stop the bloodbath."

Saudi Arabia, Egypt and Turkey reaffirmed their support for the new authorities. Turkey and the United Arab Emirates also condemned the violence. Iran, a former Assad ally, stated its opposition to the killing of "innocent Syrians."

Syrian forces include many former fighters of Hay’at Tahrir al-Sham, the Islamist group that spearheaded the coalition that overthrew Assad.

Images broadcast by SANA on Friday showed members of the new security forces entering pickup trucks in Baniyas and Tartous. In other footage, taken by AFP in Al-Bab in northern Syria, fighters in Syrian National Army fatigues — a pro-Turkish faction — prepared to head to Latakia as reinforcements for the new authorities.

The Organization of Islamic Cooperation approved Syria’s reintegration into the group on Friday, reversing its 2012 suspension after Assad’s crackdown on a pro-democracy uprising.

"This decision represents an important step toward Syria’s return to regional and international communities as a free and just state," the Syrian Foreign Ministry said in a statement.