The UN says it's receiving "extremely disturbing" reports of violence in Syria and is urging the country's new leaders to take "swift actions to protect Syrians".

In a statement, UN human rights chief Volker Türk says: "Following a series of coordinated attacks reportedly launched by elements of the former government and other local armed men, we are receiving extremely disturbing reports of entire families, including women, children and hors de combat fighters, being killed."

He says there are reports of "summary executions on a sectarian basis" carried out by unidentified perpetrators, members of the Syrian security forces, and elements linked to the former Assad government.

"There must be prompt, transparent and impartial investigations into all the killings and other violations, and those responsible must be held to account," he says.

The UK-based Syrian Observatory for Human Rights (SOHR), a war monitoring group, says that at least 1,000 people have been killed as a result of the violent clashes in over the last few days.

The organisation says that 745 civilians were killed in 30 "massacres" targeting Alawites on the west coast on Friday and Saturday. That is in addition to fighters killed over the past four days, and brings the total deaths so far to more than 1,000.

The BBC has not been able to independently verify how many people have been killed in the violence so far.

(Source: BBC)