Pakistan's military has stepped up its offensive on Taliban militants in the Bannu district of North West Frontier Province, which a military spokesman said is a "notorious hideout" for militants.
"He said he was calling from Miranshah in North Waziristan and the telephone number used to make the call carried an area code common to the Waziristan tribal area and Bannu, the adjoining district in the North West Frontier Province, " the paper said.
Police officer Amjad Khan told the Associated Press the blast hit a platoon of 43 Frontier Constabulary troops in a truck near the police district headquarters.
Also Sunday, two members of the paramilitary Frontier Corps were killed in clashes in the Bolan district of the southwestern province of Baluchistan, said government official Waheed Shah.