A shell hit a hospital in the east Ukrainian rebel-controlled city of Donetsk on Wednesday, killing or injuring several people, the city administration said.

"There was an artillery shell at 12 noon (0900 GMT)... The shell hit a hospital, there are dead and wounded," a statement on the administration's website said, adding that several schools and children's nurseries had also suffered in the blast.

It said the number of dead was being established but the Russian news agency RIA quoted rebel sources as saying that four people had been killed.

A Reuters cameraman who visited the scene said two shells had struck, one after the other, and he saw three bodies of victims.

One lay near the hospital building - Hospital No 27 in the city's southwestern Kirovsky district - while two others lay on the street near neighbouring buildings.

Earlier, the Ukrainian military said two of its soldiers had been killed and 18 wounded in fighting against pro-Russian separatists in the previous 24 hours.