Police in the western Pakistani city of Dera Ismail Khan say unidentified men opened fire on a vehicle carrying customs officials on April 21, killing a customs inspector and two security personnel and injuring another in the second deadly attack on customs officials in the span of four days.
No one claimed responsibility for either incident.
Police are investigating.
They identified the slain official as an inspector named Hasnain.
A month ago in the same town, a suicide attack killed two Pakistani troops traveling in a military convoy.
Then on April 18, five customs court staff and two other individuals were killed in an attack on a court vehicle in nearby Darabon Sago.
Some of the attacks plaguing the area around the Pakistani-Afghan border have been claimed by the Pakistani Taliban (TTP), a radical Islamist group that has been a U.S.-designated terrorist organization since 2010.
The attacks have ratcheted up already high tensions between Islamabad and the Taliban-led Afghan government.