Russia has conducted more than 50 air strikes since Tuesday against Islamic State (IS) jihadists near the eastern Syrian city of Palmyra, the defence ministry said on Thursday. 

"The Russian air force has increased the intensity of its strikes against targets of the armed units of international terrorist organisations near the city of Palmyra," it said in a statement carried by Russian news agencies. "Since July 12, Russian air force planes have conducted more than 50 strikes against Islamic State personnel and materiel in this area."