ISLAMABAD -- An explosion targeting a bus full of Pakistani police has killed at least 12 people and injured more than 50 others.
Many of the injured are said to be in critical condition.
The attack occurred on February 13 near the southern port city of Karachi.
Police said it was not immediately clear whether the explosion was set off by a suicide car bomber or a roadside bomb.
Pakistani Taliban spokesman Shahidullah Shahid claimed responsibility for the extremist group.
The latest violence comes amid peace talks between government and Taliban representatives aimed at trying to end Pakistan's violent insurgency.
Both sides are supposed to refrain from major attacks during the talks.
Earlier this week, at least 22 people were killed in attacks in the northern city of Peshawar.
Based on reporting by dpa, Reuters, AFP, AP, and RFE/RL's Radio Mashaal