The bomb attack that killed 10 people at a Moscow market on Monday was probably racially motivated, Moscow's top prosecutor Yuri Syomin has said.
The bomb went off without warning in the bustling market
Many traders at the Cherkizovsky market are from Asia and the Caucasus. Five of those killed were Chinese and one was Vietnamese, Russian officials said.
Two suspects, believed to be members of extremist organisations, have been detained by the police.
More than 30 people are still in hospital, some in a critical condition.
Police said the bomb was a home-made device brought into the market in a bag by two men.
Unnamed investigators quoted by Interfax news agency said the suspects - one of them a chemistry student - were believed to have used the internet to find out how to make a bomb.
The blast at 1030 (0630 GMT) on Monday hit a two-story trading arcade, destroying several pavilions, the supports of which collapsed, officials said.
The Russian news agency Itar-Tass reported that the two suspects were young men between 18 and 15 years old and were believed to be members of a nationalistic youth group.
Russian prosecutors are not ruling out the theory that the motivation could have been criminal, or terrorist.
Rival criminal gangs in Moscow occasionally plant small bombs at markets.
It has numerous stalls offering a wide range of goods, including leather coats, electrical products and fast food.
Russia has been plagued by a series of racially motivated attacks, some of them fatal, in recent months.