A bomb exploded Monday in the centre of the town of Nazran in Russia's troubled Caucasus region, causing several casualties, Russian news agencies reported.
A spokeswoman for the local interior ministry in the province of Ingushetia would only confirm that there had been a blast near a bank in the centre of Nazran, the region's largest town.
Interfax news agency quoted an interior ministry source as saying that "four passersby were injured. Two of them, according to preliminary information, were policemen."
The other two were employees of the bank, according to the report.
An independent news site quoted witnesses saying that the device was set off in a car and that three cars at the scene were damaged.
Ingushetia is in the heart of the restive Caucasus mountains and borders Chechnya, where separatist guerrillas have spent much of the last 14 years battling Russian forces. (AFP)
Bomb explodes in centre of Russian city