Beijing - Seven Chinese nationals were injured in a bomb blast that tore through a market in Russia, the official Xinhua News Agency said Tuesday.

The Chinese Embassy in Moscow has not received information on whether any Chinese were killed, Xinhua said, citing an unnamed embassy official. It did not give any details on the injured.

The explosion Monday morning was caused by a homemade bomb and hit a two-story trading arcade in the northeastern part of Moscow, Russian news agencies have reported.

At least 10 people were killed and another 31 were injured as a 200-square-meter (2,150-square-feet) section of the market collapsed, the reports said.

The general prosecutor's office had opened a murder investigation, indicating that police may believe the blast was connected with organized crime or a business dispute rather than terrorism.

The bombing, at the Cherkizovsky Market in northeastern Moscow, occurred amid heightened fears of terrorist attacks, but the city's chief prosecutor, Yuri Syomin, blamed the blast on gangs fighting over control of lucrative and largely unregulated markets.

A large number of traders in the Cherkizovsky market come from Asia or the restive Caucasus regions and both ethnic groups have been victims of a growing wave of hate crimes in Russia.

Syomin said the blast had been caused by a homemade bomb of a force equivalent to about 1.2 kilograms, or 2.6 pounds, of TNT, Reuters reported. It destroyed more than 185 square meters, or 2,000 square feet, of the market's roof.

There were 40 wounded in the blast, several of them seriously, suggesting that the death toll could rise still higher.

By Monday evening, Russian news agencies, citing unnamed officials, reported that two men had been arrested, but provided few details on the motive.

Appearing outside the market, which was severely damaged, Syomin said that "criminal elements" were responsible for the violence.

"Either it was a collision of major commercial interests or a trivial instance of gang war," he said.

Russia's open-air markets are labyrinths of hawking traders and haggling shoppers, where physical movement is at best limited.

They have long been battlegrounds for mafia groups. In the 1990s, gunfights were common.

Many of those killed, Interfax reported, were foreign migrants, which raised the possibility of an ethnically motivated attack in a city where such crimes are common.

The two suspects detained after the blast Monday were captured by workers at the market, who noticed that three people had dropped a bag outside of the stalls in blast area. A third suspect escaped, Interfax reported.

Within 30 minutes, the area around the bomb site was sealed off by both local security and the police.

The walkways were clogged with men hauling carts piled with goods fleeing the immediate area of the explosion.

Most of the market, however, continued with business as usual. Most onlookers only shook their heads at the nearby destruction.

"It was terrible - I saw puddles of blood, it was literally everywhere. One body was without a head," Reuters reported a Central Asian trader, who gave his name as Alik, as having said.

"It hit an area near a Chinese cafe," he said. "The whole place was soaked in blood."