Russia's Interior Ministry

The international auction house Sotheby's said on May 31 it would proceed with the auction of a painting by a famous Russian artist that the Russian authorities had said was stolen. 

Russian opposition politician and former Deputy Prime Minister Boris Nemtsov has been shot dead in central Moscow.

Nemtsov was shot four times in the back by an unknown attacker, according to a law enforcement source, as cited by the Interfax news agency.

The killer is said to have escaped in a car.

The incident happened at around 23:40 local time near the Kremlin.

At least five people have died after two trains collided south-west of the Russian capital Moscow, Tuesday.

Five people died and 15 were injured as a freight train hit a passenger train, according to a preliminary report from Russia's Interior Ministry.