Twenty soldiers were killed and more than thirty others were wounded on Sunday as a bomb ripped through a military convoy in the restive northwest.

Twenty soldiers were killed and more than thirty others were wounded on Sunday as a bomb ripped through a military convoy in the restive northwest.

Officials said the attack took place in the city of Bannu, near the North Waziristan tribal region which is a known stronghold of militants linked to the Taliban and Al-Qaeda.

"A vehicle-borne improvised explosive device caused the blast," a senior military official told AFP, adding the exact circumstances were unclear.
"The explosion took place in one of the vehicles of the convoy, killing 20 soldiers and wounding more than 30," he said on condition of anonymity.

The official said the convoy was about to leave for the town of Razmak in North Waziristan when the blast hit one of the civilian vehicles hired to move troops.
A Frontier Corps official confirmed the attack and casualties.

Tehreek-e-Taliban Pakistan (TTP) spokesman Shahidullah Shahid claimed responsibility.
"It was part of our fight against a secular system," he told AFP by telephone from an undisclosed location.
"We will carry out more such attacks in future."

An eyewitness told AFP by telephone that the vehicle hit by the bomb was transformed into scorched metal.
"I collected human remains including hands and legs from the site after the attack," he said on condition of anonymity.

Body parts and soldiers' personal belongings littered the scene.
"I also helped rescue workers in moving injured people to ambulances," the witness added.
Bannu has been the scene of several past attacks on security forces.