Pakistani officials say suspected U.S. missile strikes killed at least six militants in Pakistan's northwest Monday.
The officials said six missiles fired by two U.S. drones hit a house and vehicle in the Datta Khel region of North Waziristan tribal area bordering Afghanistan.
In southwestern Baluchistan province, police say militants set fire to three NATO tankers transporting fuel for U.S.-led coalition forces in Afghanistan.
The attack came just days after Pakistan re-opened the border crossing following an 11-day closure imposed after a cross-border airstrike by NATO forces.
In other violence Monday, a suicide car bomber attempted to attack a military checkpoint in the northwestern district of Lakki Marwat, but security forces shot him dead. Three people were wounded in the resulting explosion.
Thirty-one people were killed in election-related violence Saturday and Sunday in Pakistan's southern port city of Karachi.
The unrest broke out late Saturday when gunmen opened fire in several parts of the city ahead of the vote. Police have arrested at least 20 suspects in connection with the killings.
The election was being held Sunday to replace provincial lawmaker Raza Haider from the Muttahida Quami Movement (MQM), who was gunned down in August.
Some information for this report was provided by AFP and Reuters.