Hundreds of people were killed in Syria over four days after violent clashes between the army and loyalists of the deposed president Bashar al-Assad swept its western coastal region.

What began as an ambush on Syrian security patrol by Assad loyalists brought havoc to several cities and towns on the coast.

The attack sparked the worst violence Syria has seen since the end of 13 years of conflict in the country, coming three months after the Assad regime was overthrown in an offensive by opposition fighters led by the Sunni-Islamist group Hayat Tahrir al-Sham, or HTS.

Here’s what we know so far about the attacks and where things currently stand in the region.

How did the violence erupt?

The violence unfolded on Thursday, after a surprise attack by gunmen from the Alawite community on a police patrol near the port city of Latakia spiralled into widespread clashes across Syria’s coastal region.

The attacks — which appeared to be co-ordinated — were a major escalation and a challenge to the new government in Damascus, where the former insurgents now in power have pledged to unite Syria after more than 50 years under the Assad dynasty.

In their ambush, the armed pro-Assad fighters overwhelmed government security forces and later took control of Qardaha, Assad’s hometown, as Damascus scrambled to bring in reinforcements.

The majority of the population in the coastal cities are members of the ousted president’s Alawite sect, an offshoot of Shia Islam.

The Alawites previously formed the core constituency of Assad’s government in the Sunni-majority country, linking the community to the regime’s brutal rule over Syria, in the eyes of its opponents. But many Alawites said that they suffered like other Syrians under the rule of Assad and his father, Hafez al-Assad.

Eyewitness reports and videos from the coastal region showed houses in several neighbourhoods set on fire and bloodied bodies laid on the streets. Many residents said they were too afraid to leave their homes.

The government poured reinforcements to coastal cities, including Latakia, Banias, Tartous and Jableh, to crush what it described as a deadly, well-planned and premeditated assault by remnants of the Assad regime.

On Monday, the government said it had ended its military operation in Latakia and Tartous.

Syria’s interim president, Ahmed al-Sharaa, later acknowledged that some armed groups had entered without prior co-ordination with the Defence Ministry.

The Syria Campaign and the Syrian Network for Human Rights (SNHR) said Saturday that both security forces and pro-Assad gunmen were “carrying out mass executions and systematic killings.”

Who was targeted?

Despite authorities calling for an end to the sectarian incitement, the clashes turned deadly, and many civilians were killed.

Between Thursday and Monday, roughly 779 people were killed, according to the SNHR.

The SNHR told CBC News in a statement that at least 383 people were killed by remnants of the Assad regime. 

Of those 383 people, 172 were members of the General Security Forces and 211 were civilians. 

CBC News could not independently verify these numbers.

Meanwhile, armed forces — composed of military factions, armed local residents (both Syrian and foreign) and members of the general security forces — were responsible for the deaths of at least 396 people, according to SNHR.

“Distinguishing between civilians and disarmed members of the Assad regime has proven particularly challenging, as many of them were dressed in civilian clothing,” the organization said. 

The SNHR also noted that its death tolls exclude “combat-related” fatalities among the Assad loyalists, “as such deaths are not classified as violations of international law.”

CBC News’s verification team has verified a video posted on Saturday by the Syrian Coast Observatory on Telegram, showing men in Public Security Forces uniform shooting at unarmed people in civilian clothes. Five bodies of people killed were shown on video.

The UN human rights office said Tuesday entire families, including women and children, were killed as part of a series of sectarian killings by the army against an insurgency by Assad loyalists.

How has the new government responded?

Defence Ministry spokesperson Hassan Abdel Ghani said Sunday that security forces have restored control of the region and will continue pursuing leaders of the galvanized insurgency.

Four people were arrested Tuesday by the Public Security Department for allegedly committing illegal and bloody violations against civilians in the region, according to Syria’s state news agency SANA.

On Monday, Sharaa told Reuters that he could not yet say whether forces from Syria’s Defence Ministry — which has incorporated former rebel factions under one structure — were involved in the sectarian killings.

“Syria is a state of law. The law will take its course on all,” he told Reuters in an interview.

“We fought to defend the oppressed, and we won’t accept that any blood be shed unjustly, or goes without punishment or accountability, even among those closest to us.”

Sharaa blamed pro-Assad groups backed by foreigners for triggering the bloodshed but acknowledged that revenge killings had followed.

Sharaa, appealing to Syrians and the international community in an address over the weekend, called for accountability for anyone who harms civilians and mistreats prisoners and said said Syria will not be dragged into civil war. 

WATCH | Hundreds in Syria killed in deadly clashes: 

More than 1,000 civilians reported killed as violence in Syria spirals

The UN is urging Syria’s interim leaders to protect civilians amid fighting between security forces and those who remain loyal to ousted Syrian president Bashar al-Assad. Former army personnel allied to Assad have been carrying out co-ordinated attacks and ambushes since Thursday.

The Syrian fact-finding committee investigating sectarian killings said it would seek the arrest and prosecution of any perpetrators involved.

“No one is above the law, the committee will relay all the results to the entity that launched it, the presidency, and the judiciary,” the committee’s spokesperson Yasser Farhan said in a televised news conference Tuesday.

The committee was preparing lists of witnesses to interview and potential perpetrators, and would refer any suspects with sufficient evidence against them to the judiciary, Farhan added.

What has happened since?

Several demonstrations were held in Syria following the onslaught of violence.

Syrians gathered Tuesday in Latakia to demonstrate against the recent mass killings.

“One, one, one. The Syrian people are one,” demonstrators chanted in videos out of Latakia, calling for security in the region and for protection from the government against sectarian violence.

The Syria Campaign shared a statement on Instagram Tuesday following the events. 

“Our hearts break for all the families who lost loved ones to [the] horrific massacres,” it said, adding that many are still unable to bury their loved ones while others are flee their homes in fear for their lives. 

“Indifference equals complicity. Speak up against these atrocities and demand accountability and justice for all,” the statement said.

Since Assad was ousted, Sharaa has pledged to run Syria in an inclusive way. 

While many Syrians believed the Alawites were favoured under Assad, who had included many senior bureaucrats and military officers, thousands have continued to call for unity among all sects since the new interim government was formed. 

The UN refugee agency said in a statement that 6,078 Syrians have arrived in about a dozen villages in northern Lebanon’s Akkar province after fleeing the fighting in Syria’s coastal area, according to local authorities.