国际英语新闻：Russian president vows to punish those behind deadly blast in North Ossetia

The powerful explosion ripped through the central market in Vladikavkaz on Thursday morning. According to the latest figures, 114 people were injured.

Many of the injured were in critical condition, and some would be sent to Moscow hospitals, a medical source said.

The blast, equivalent to about 30 kilos of TNT, was caused by a car bomb. The car used to carry the explosive was parked near the market in Zanayev Street, a local police source said.

Soon after the blast, another explosive device was found near the entrance to the market.

Hours later, the owner of the vehicle, a man named Dobriyev, was arrested, the police said.

"The car owner named Dobriyev has been apprehended and is being questioned," a North Caucasian federal district police officer told Interfax.

The detainee claimed that he sold his vehicle to an unknown man on Wednesday, the officer said.

"The suicide bomber who blew up the Volga parked near the market was blown to pieces and can only be identified by DNA tests," a local Interior Ministry official said.

MOSCOW SECURITY TIGHTENED

In wake of the deadly attack, police bolstered security in Moscow, police spokeswoman Zhanna Ozhimina told Interfax.

"In connection with the Vladikavkaz terror attack, Moscow police chief Vladimir Kolokoltsev instructed district police heads to brief officers to be more vigilant, and to concentrate on instructions issued by the Interior Ministry and the National Anti-Terror Committee," Ozhimina said.

Road traffic police have been told to remain alert for suspicious vehicles entering Moscow, especially motor vehicles with North Caucasus number plates, she said.

North Ossetia, as well as its neighboring Dagestan and Chechnya, have seen increasing violence in recent years.

The Vladikavzak market has been the target of two previous terrorist attacks.

In 1999, an explosion in the market killed 55 people and injured some 300 others. In 2008, 12 people were killed and over 40 wounded in a bus bombing.