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.
French police have foiled a terror attack on police and army personnel in the region of Orleans, the interior minister has said.
At least 200 civilians are killed in Russian air strikes in Syria, an Amnesty International report says, quoting witnesses and activists.
The killing of minorities by so-called Islamic State should be recognised as genocide, more than 60 parliamentarians say in a letter to the UK PM.
Vladimir Putin has said Russia is using "far from everything we are capable of" in its military operations in Syria.
The United Nations Security Council on Friday unanimously approves a resolution endorsing an international road map for a Syria peace process, a rare show of unity among major powers on a conflict that claimed more than a quarter million lives.
Controversial plans for an EU Border and Coast Guard force are to be set out as part of an EU drive to curb the record influx of migrants.
US Secretary of State John Kerry is in Moscow for talks to try to bridge gaps with Russia over the political process to end Syria's civil war.
At least 45 civilians are killed Sunday in heavy bombardment of a besieged Syrian rebel stronghold east of Damascus that also struck a school, a monitoring group said.
The first military plane carrying Syrian refugees to be resettled in Canada has arrived in the country.
Syrian rebels begin evacuating the last area they hold in the city of Homs under a ceasefire deal reached with the government, a monitoring group has said.
