The United Nations special envoy for Syria has condemned an intense wave of Israeli airstrikes as Israel said its forces were on the ground in Syria to protect the Druze minority sect following days of clashes with Syrian pro-government gunmen.

It was the second time in days that Israel intervened militarily in Syria amid a wave of sectarian violence there.

Israel said it carried out a strike in Syria against "an extremist group" that attacked members of the Druze community, following through on a promise to defend the minority group as deadly sectarian violence spread near Damascus on Wednesday.