The suicide bomber who blew himself up at a police checkpoint in North Ossetia was part of a gang allegedly heading for Moscow, a police source in the republic said on Tuesday.

"According to information at hand, the group was heading to Moscow from Chechnya. One can say for sure that our officers prevented grave terrorist attacks at the cost of their own lives," the source said.

An accomplice of the suicide bomber has been detained, the source said, adding he was being questioned by the republic's security services.

Earlier on Tuesday, Russia's North Ossetian Investigative Committee said the suicide bomber killed two policemen, leaving three others injured.

The North Ossetian Interior Ministry said there was only one policeman killed and three wounded.

"I am at the scene of the crime and can say for sure that there was one policeman killed," the deputy head of the North Ossetian Interior Ministry's press service, Samir Sabatkoyev, told RIA Novosti.

The attacker was crossing a police checkpoint at the border between the North Caucasus Republic of Ingushetia and North Ossetia. When a policeman asked him to produce his identification, the terrorist blew himself up, the North Ossetian Interior Ministry said.

The republic's Health Ministry said the injured law enforcers were delivered to hospitals in the city of Beslan.

All three received shrapnel wounds and contusions, the ministry said.

VLADIKAVKAZ, August 17 (RIA Novosti)