Islamabad, July 8 : Pakistani security agencies are reportedly zeroing in on the banned extremist groups - Jaish-e-Muhammad and Sipah-e-Sahaba - having links with Al Qaeda, to be behind Sunday's Islamabad suicide blast killing 20 people. No suspects have been detained so far.
The security officials, however, said that they didn't have firm leads about these terrorist organizations' role in the blast. "We have no firm leads but we are examining the possibility that some of these groups may have been involved or were in league with followers of Lal Masjid," the Daily Times quoted a senior security official as saying in an interview with a foreign news agency.
There was no immediate claim of responsibility for the blast, but security officials said that they were examining a range of possible culprits, including the mosque's former students and local Taliban militants, reported the paper.
Police investigator Falak Sher said that around 5-kg explosives was used in the attack.
Meanwhile, the police reportedly recovered the head of the suspected suicide bomber. Investigators made the gory find on a nearby rooftop during the investigation at the scene of the blast.
The sketch of the suspected bomber had been given to the authority for identification, sources in the National Database and Registration Authority said and added that it would be made public soon.