PESHAWAR: Police investigating a suicide bombing that killed more than 100 people at a Pakistan mosque said on Tuesday that several people had been arrested, and they could not rule out the possibility that the bomber had internal assistance evading security checks.

The bombing was the deadliest in a decade to hit Peshawar, a restive northwestern city near the Afghan border, and all but three of those killed were police, making it most suffered by Pakistan’s security forces in a single attack in recent history.

The bomber struck on Monday as hundreds of worshippers gathered for noon prayers in a mosque that was purpose built for the police and their families living in a highly fortified area.

“We have found some excellent clues, and based on these clues we have made some major arrests,” Peshawar Police Chief Ijaz Khan told Reuters.
“We can’t rule out internal assistance but since the investigation is still in progress, I will not be able to share more details.”

Investigators, who include counter-terrorism and intelligence officials, are focusing on how the attacker managed to breach the military and police checkpoints leading into the Police Lines district, a colonial-era, self-contained encampment in the city center that is home to middle- and lower-ranking police personnel and their families.

Defense Minister Khawaja Asif had said the bomber was in the first row in the prayer hall when he struck. Remains of the attacker had been recovered, provincial Police Chief Moazzam Jah Ansari told Reuters.

“We believe the attackers are not an organized group,” he added.

The most active militant group in the area, the Pakistani Taliban, also called Tehreek-e-Taliban Pakistan (TTP), has denied responsibility for the attack, which no group has claimed so far. Interior Minister Rana Sanaullah had told parliament a breakaway faction of the TTP was to blame.

The blast demolished the upper story of the mosque. It was the deadliest in Peshawar since twin suicide bombings at All Saints Church killed scores of worshippers in September 2013, in what remains the deadliest attack on the country’s Christian minority.

Peshawar sits on the edge of the Pashtun tribal lands, a region mired in violence for the past two decades.

The TTP is an umbrella group for Sunni and sectarian Islamist factions opposed to the government in Islamabad. The group has recently stepped-up attacks against police.