A nuclear scientist who supervised a department at the Natanz uranium enrichment facility has been killed by a magnetic bomb placed on his car by two assailants in northern Tehran, Iranian media reported.

The attack strongly resembles earlier killings of scientists working on the country's controversial nuclear programme.

The bomb explosion killed Mostafa Ahmadi Roshan, a chemistry expert and a director of the Natanz facility in central Iran, the semi-official Fars news agency reported.

Vice President Mohammad Reza Rahimi said Israeli agents were behind the attack, but said they cannot "prevent progress'' in what Iran claims are peaceful nuclear efforts.

Al Jazeera's Dorsa Jabbari reports from Beirut, Lebanon.