Islamabad: Pakistan's Interior Ministry has directed law enforcement agencies to arrest three activists of the banned Sunni extremist group Lashkar-e-Jhangvi for their suspected involvement in the Peshawar suicide bombing, which left 15 persons dead including the city police chief.

LJ activists Jalil Ahmed, Ilyas Moawia and Nazir Ahmed are suspected of orchestrating the blast, officials here said.

The Interior Ministry issued the directive following reports that the three had been planning to target Shias in Peshawar and Hangu during the Muharram period during which Sihas take out traditional processions to hightlight the sacrifices of their spiritual leader, Imam Hussain.

Three teams have been formed to investigate Saturday's suicide attack, and police had been deployed in extra strength for peaceful Muharram processions.

Ten persons, including the Peshawar Police Commissioner and four top police officials, were killed in a suicide bomb attack on a Muharam procession in Peshawar on Saturday last.

"Teams for the collection of evidence, investigation and arrest purposes have been formed," new Peshawar police chief Abdul Majeed Marwat was quoted by Daily Times as saying.

Majeed said statements by injured policemen and other people had not yet been recorded, but when this was done, it could provide police with more clues.

The police official said it was difficult to suggest whether the suicide bomber was targeting police officials, but Adviser to Chief Minister Allama Ramzan Tauqir said police had been targeted in the attack.