Suspected Chechen rebels on Monday rammed an explosive-laden truck into the regional headquarters of Russia's Federal Security Services in Ingushetia, killing two persons and injuring 40.

At least 100 people were inside the building, which was severely damaged, the ITAR-TASS agency said.

Among the dead was Mikhail Safonov, a deputy director of the FSB branch in Chechnya, according to the Interfax news agency.