Syria's new authorities launched an operation Thursday in a former stronghold of ousted dictator Bashar Assad, killing three gunmen linked to the previous regime, according to a war monitor.

Assad fled Syria after an offensive by an anti-regime alliance wrested from his control city after city until Damascus fell on Dec. 8, ending his clan's five-decade rule and more than 13 years of civil war.

Syria's new leaders from the Hayat Tahrir al-Sham (HTS) group face the monumental task of safeguarding the multi-sectarian, multi-ethnic country from further collapse.

With 500,000 dead in the war – sparked by Assad's crackdown on democracy protests – and more than 100,000 missing, the new authorities have also pledged justice for the victims of abuses under the deposed ruler.

On Thursday, state news agency SANA said security forces launched an operation against pro-Assad militias in the western province of Tartus, "neutralizing a certain number" of armed men.

According to the Syrian Observatory for Human Rights monitor, three gunmen linked with Assad's government were killed in the operation.

It comes a day after 14 security personnel of the new authorities and three gunmen were killed in clashes in the same province when forces tried to arrest an Assad-era officer, according to the Observatory.

The Britain-based monitor said the wanted man, Mohammed Kanjo Hassan, "held the position of director of the military justice department and field court chief" at the notorious Saydnaya prison complex.

It said he had "issued death sentences and arbitrary judgments against thousands of prisoners."

Hate or revenge

The Saydnaya complex, the site of extrajudicial executions, torture and forced disappearances, epitomized the atrocities committed against Assad's opponents.

The fate of tens of thousands of prisoners and missing people remains one of the most harrowing legacies of his rule.

During the offensive that precipitated Assad's ousting, anti-regime forces flung open the doors of prisons and detention centers around the country, letting out thousands of people.

In central Damascus, relatives of some of the missing have hung up posters of their loved ones, in the hope that with Assad's ouster, they may one day learn what happened to them.

World powers and international organizations have called for the urgent establishment of mechanisms for accountability.

But some in the Alawite community, which Assad belonged to, said they fear attacks from groups seeking revenge or hate.

On Wednesday, there were protests in several areas around Syria, including Assad's hometown of Qardaha, over a video allegedly showing an attack on a shrine.

The transitional authorities said in a statement that the attack was old while the Interior Ministry said the attack was carried out by "unknown groups" and that "republishing" the video served to "stir up strife among the Syrian people at this sensitive stage."

Images from the coastal city of Jableh, north of Tartus, showed large crowds in the streets, some chanting slogans including "Alawite, Sunni, we want peace."

Assad long presented himself as a protector of minority groups in Sunni-majority Syria.