The blast was caused by a device placed on the car's roof

The Russian Interfax news agency reported that a device had exploded as Magomedsalikh Gusayev was driving to work on Wednesday.

Interfax quoted witnesses as saying two men had placed a bomb on the roof of the car carrying the minister to his office, as it drove out of the compound where he lived.

His driver survived the attack and is being questioned by police.

Targeted

Mr Gusayev was also minister for national policy in the north Caucasian republic, which borders Chechnya.

He survived an attempt on his life on 8 June 2001, when a bomb exploded by the entrance to his house as he stepped out of the building.

He had previously received death threats from Islamic extremists in 1999, Interfax quoted police officials as saying.

Mr Gusayev was thought to have been singled out as a target after he helped fend off an invasion of Dagestan by Chechen Islamic extremists in 1999.

The Russian military continues to fight a decade-long separatist insurgency in Chechnya.

One man was killed and two seriously injured after a helicopter came down in Chechnya earlier this month.