Syria's new authorities under interim President Ahmed al-Sharaa have sought to disband armed groups
The Syrian Observatory for Human Rights war monitor has reported that 745 Alawite civilians were killed in Latakia and Tartus provinces.
Syrian authorities said the violence began when remnants loyal to Assad launched a deadly and well-planned attack on their forces on Thursday.
There were no immediate claim of responsibility for the attack.
Sharaa was appointed Wednesday to lead Syria for an unspecified transitional period
No group has claimed the four activists' abduction and they have not been heard from since.
Ankara-backed rebels played a key role in supporting Sharaa's Islamist group Hayat Tahrir al-Sham (HTS), which headed a rebel alliance that seized Damascus on December 8, toppling longtime ruler Bashar al-Assad.
The seismic change in Syria is expected to yield deeper Turkish sway just as a change of US administration is raising questions over how long Washington will keep backing the country's Kurdish-led forces.
Assad fled Syria following a lightning offensive spearheaded by the Islamist Hayat Tahrir al-Sham (HTS), more than 13 years after his crackdown on democracy protests precipitated one of the deadliest wars of the century.
A monitoring group says, since last three months, the Islamic State has recruited at least 400 children in Syria and trained them as so-called "Cubs of the Caliphate" and hard line indoctrination.
Nine British medical students and doctors are feared to has travel to Syria to work in areas controlled by Islamic State militants.
The US defence department says it is investigating an online threat allegedly made by Islamic State to about 100 of its military personnel, and posted a list of the names and addresses on a website linked to the group alongside a call for them to be killed
Chechen woman living in Netherlands takes her two young children against their father's will to join Islamic State (IS) militants in Syria
Three teenagers who were stopped from travelling to Syria from Turkey are flown back to the UK and arrested, Scotland Yard says
Three teenagers who were stopped from travelling to Syria from Turkey have been flown back to the UK and arrested, Scotland Yard has said.
The Vatican's ambassador to the United Nations endorses military action against the Islamic State group in Iraq and Syria -- an unusual move because the Vatican traditionally has opposed force in the region
Islamic State (IS) accepts pledge of allegiance from Nigeria's militant group Boko Haram, according to an audio message
Melbourne schoolboy who travelled to Middle East to fight with Islamic State (IS) dies in suicide attack in Iraq
US-led coalition air strike in Syria hits an oil refinery run by the Islamic State militant group killing 30 people
