ISLAMABAD - Pakistans security agencies have stepped up efforts to track down the perpetrators of the suicide bombing at Rescue-15 Building in Lahore, TheNation learnt from military sources on Wednesday. Security agencies are working on different leads, including the probability that the incident might be a militants reaction to the ongoing operation in Malakand region, a senior security official said. He was of the view that armed militants in Malakand division, especially in Swat district, had suffered huge losses and were too weak to resist the security forces further. Involvement of foreign hands in the incident can not be ruled out, he said adding since militants were being aided by foreign sources through Afghanistan, therefore, it would be 'nanve to rule out that possibility. It was learnt that suspects rounded up from the crime scene strongly suggests that the perpetrators organised the attack as a reaction to the ongoing security forces operation. Senior defence analysts support this perception, as they believe that militants having lost battle in Swat and Malakand, seem to be opting for such actions as their last resort. General (Retd) Talat Masood, one of the leading defence analysts, told a private TV channel that Lahore suicide bombing was direct reaction to the security forces operation in Malakand. Former Interior Minister Aftab Ahmed Khan Sherpao also holds the same opinion and emphasises the need for further streamlining the intelligence system to help avert such incidents in future. PML-N senior leaders including Punjab Law Minister Rana Sanaullah held it could be handiwork of foreign hands.