DONETSK, November 6. /TASS/. The head of the self-proclaimed Donetsk People's republic, Alexander Zakharchenko, signed a decree on Thursday declaring November 6 and 7 days of mourning for two school children killed in a shelling that destroyed a school.

The children were killed on Wednesday while playing on the school sports field in Donetsk. Three other locals, reportedly aged between 17 and 21, sustained various injuries and were hospitalized.

Russia’s Investigation Committee said earlier on Thursday a criminal probe had been launched into the deadly school shelling in Donetsk. According to investigators, on Wednesday afternoon servicemen of Ukraine’s Armed Forces and National Guard launched artillery shelling upon instructions of their commanders directly targeting school number 63 in Donetsk.

Investigators suspect that the attack was launched to “eliminate a Russian-speaking ethnic group living on the territory of the self-proclaimed Donetsk People’s Republic,” the committee's spokesman, Vladimir Markin, said.

The shelling comes in violation of international conventions, including the United Nations Convention on the Rights of the Child as well as the protocol on ceasefire in eastern Ukraine and the memorandum signed in the Belarusian capital Minsk in September.