Nearly 30 air strikes have hit rebel-held areas of Syria's northern city of Aleppo, killing at least five people.

A monitor group said the air strikes were believed to have been carried out by Syrian government warplanes. The group puts the total number of people killed by the warring sides to nearly 250, after nine straight days of bombardment.

However, the Syrian army announced what it called a temporary "regime of calm" late on Friday. It appeared to have taken hold in the northwestern coastal province Latakia, and outskirts of the capital Damascus. Russia says it will not ask the Syrian government to halt air raids on Aleppo, saying the strikes are helping to combat jihadist groups.