Islamabad, Aug 17 (IANS): A First Information Report (FIR) was filed on Monday on the killing of Col. Shuja Khanzada (retd), the home minister of Pakistan's Punjab province, in a suicide bomb attack which destroyed his office in Attock city.

The FIR was lodged by the Station House Officer (SHO) of Rangoo police station, Ghulam Shabbir, on behalf of the state against all those involved in the suicide attack targeting Khanzada, Dawn online reported.

The report of an initial investigation given to Punjab Chief Minister Shahbaz Sharif revealed that the home minister was killed in retaliation for the deaths of Lashkar-i-Jhangvi chief Malik Ishaq and others.

The attack on Punjab home minister Colonel (retd) Shuja Khanzada took place on Sunday when he was at his political office in Attock district's Shadi Khan village. More than 35 people had gathered to pay condolence for a close relative of the minister who had died on Saturday in Britain.

Eighteen others were killed in the attack, including Deputy Superintendent of Police (DSP) Hazro Police Shaukat Ali Shah, who was providing security to Khanzada.

Inspector General of Police Mushtaq Sukhera told reporters at the blast site that there was a possibility that there were two suicide bombers who struck the building.

He added that a head of a calf was also found in the debris, due to which the police would also investigate if an animal had been used in the attack; the intensity of the blast appears to be far more than what can be caused by a suicide jacket.

It is the first time that such an attack has been carried out on a high-profile member of the Pakistan Muslim League-Nawaz (PML-N), particularly in Punjab.