Rapid Action Battalion has filed a case accusing seven to eight unknown persons in connection with the yesterday’s suspected suicide attack at a barrack of the elite force in Dhaka’s Ashkona area yesterday.

Rasheduzzaman, a sub-inspector of Rab, filed the case with Airport Police Station under Anti-Terrorism Act this morning, said Nur-e-Azam, officer-in-charge of the police station.

A “suicide bomber” yesterday sneaked into the Rab barrack and blew himself up, in what appears to be the country's first such attack by a terror suspect inside a law enforcement agency's compound.

The attacker, who is yet to be identified, died instantly while two Rab members suffered splinter injuries.

READ: Man ‘carrying bombs’ killed in Rab firing at Dhaka check post

Following the attack, all prisons across the country have been put on alert while security has been stepped up at all domestic and international airports and Rab offices.

Terror group Islamic State (IS) claimed credit for the suicide attack, according to a report of BBC Bangla.

US-based SITE Intelligence, which monitors jihadist activities, also reported the attack.