ISLAMABAD - A powerful bomb blast inside an Islamic seminary in northwestern Pakistan early Tuesday, killed at least eight people and injured more than 130 others.

Police officials say an improvised explosive device ripped through the packed seminary in Peshawar city during early morning classes.

Mobile phone footage showed a cleric was teaching verses from the Muslim holy book of Quran when the bomb went off at the Jamia Zubairia madrassa (seminary).

A senior police officer, Mansoor Aman, told reporters the explosive device was hidden in a bag someone left at the madrasa.

Witnesses and rescue workers said mostly young children were among the victims.

There was no immediate claim of responsibility for the deadly bombing.

Hospital officials expected the death toll to rise.

The deadly bombing drew strong condemnation from Pakistani leaders.

Prime Minister Imran Khan said he was "deeply saddened" by the terrorist attack I want to assure my nation we will ensure the terrorists responsible for this cowardly barbaric attack are brought to justice as soon as possible.

"I want to assure my nation we will ensure the terrorists responsible for this cowardly barbaric attack are brought to justice," Prime Minister Imran Khan said. Peshawar, the capital of Pakistan's Khyber Pakhtunkhwa province bordering Afghanistan, has for years been the scene of militant attacks blamed on the outlawed Pakistani Taliban outfit.

Peshawar, the capital of Pakistan's Khyber Pakhtunkhwa province bordering Afghanistan, has for years been the scene of militant attacks blamed on the outlawed Pakistani Taliban outfit.

However, Pakistani security forces' sustained operations against the group has significantly brought down the violence over the past several years.