Pakistani police on Monday said an initial investigation revealed that the terrorist group Islamic State might be behind the suicide attack on a political gathering in Khyber Pakhtunkhwa which left 46 people dead.

According to local media reports, the blast left over 100 people hurt.

The blast occurred when a suicide bomber set off explosives at the rally on Sunday in the former tribal area which is located close to the Afghanistan border.

Emergency was declared in the hospitals of Bajaur and adjoining areas where most of the injured were taken, District Police Officer (DPO) Nazir Khan told Geo News.

The critically injured people were transported from Bajaur to hospitals in Peshawar by military helicopters.

"We are still investigating and gathering information on the Bajaur blast. The Initial probe shows that banned outfit Daesh was involved," the law enforcers told Geo News.

DPO Khan said three suspected people had been taken into custody.

Pakistan witnessed a surge in terror activities since last year when a ceasefire between the Tehreek-e-Taliban Pakistan (TTP) and Islamabad broke down.