MOSCOW, Oct. 18 (Xinhua) -- The death toll from an attack on a college in the city of Kerch in Crimea has risen to 20, as local authorities started to hold a three-day mourning, Russian media reported Thursday.

"A total of 20 people died ... Seventeen of them have been identified," Dilyaver Melgaziyev, deputy head of the Kerch city administration, was quoted by Sputnik news agency as saying.

The official also said that 10 people were severely wounded, among whom eight were identified.

The Russian Health Ministry earlier put the death toll at 19.

On Wednesday, a student opened fire and detonated an explosive at the Kerch Polytechnic College in Crimea. He later committed suicide.

The attack was thought to be an act of terrorism, but police later classified it as murder.