ISLAMABAD - At least 50 people were killed and over 100 others were injured when a suicide bomb attack hit a mosque packed with hundreds of prayers in northwest Pakistan Friday afternoon, reported local Urdu TV channel Express.

According to the TV, the blast took place at about 02:00 pm local time Friday when a teenager suicide bomber aged about 16 blew himself up in a mosque at the Ghondi area of Jamrud, a district in Pakistan's northwest tribal area of Khyber Agency which borders Afghanistan.

Hundreds of people were offering Friday prayers inside the mosque when the attack took place, said local media reports.

Some reports said that over one hundred people were inside the mosque hit by the blast while others put the number at 500 to 700 people.

Local TV footage showed that the mosque partially collapsed following the huge blast and many people were feared buried under the debris of the collapsed building.  

An estimated 40 people injured in the blast were rushed to nearby hospitals while some 50 critically injured people have been shifted to the Lady Reading Hospital in Peshawar, a city which is about 50 kilometers away from the blast site.

As the mosque hit by the blast is located in a mountainous area and some of the injured people being shifted to Peshawar could die on the way.