A series of hostilities in southern Syria involving Bedouin tribes and the Druze religious minority has reportedly left more than 1,000 people dead.

The UK-based Syrian Observatory for Human Rights said on Sunday that the death toll due to the clashes, executions and Israeli airstrikes since July 13 has risen to 1,017 people.

It said they included scores of civilians, including women and children.

In the southern city of Sweida, Bedouins and Druze clashed last week, prompting Syria's interim government to deploy troops to intervene.

Israel conducted airstrikes in southern Syria and the country's capital Damascus, saying it aimed to protect the Druze community.

The interim government declared a comprehensive and immediate ceasefire on Saturday.

But the Syrian Observatory for Human Rights said sporadic clashes occurred in the suburbs of Sweida on Sunday.

Shortages of drinking water, food and other supplies have also been reported, in a sign of deteriorating humanitarian conditions there.

The interim government said on Sunday a Druze-affiliated armed group denied entry to a convoy carrying humanitarian aid to the area. It said only a limited number of vehicles were allowed to proceed.

It remains uncertain whether the situation will be brought under control anytime soon.