The attack wounded three soldiers, according to a military official who said troops disrupted the attack in the town of Miran Shah by opening fire on the vehicle, causing it to explode before it reached the checkpoint. The official spoke on condition of anonymity because he was not authorized to talk to the media.
The discrepancy between the two accounts could not immediately be explained.
North Waziristan is believed to be an important base for al-Qaida and Taliban militants who have been staging cross-border attacks against U.S. and NATO troops in Afghanistan.
A suspected U.S. drone fired two missiles at an alleged militant hide-out Saturday in North Waziristan, killing 13 people, intelligence officials and residents said.
The dead and injured included local and foreign militants, but women and children were also killed in the attack, said the officials, who spoke on condition of anonymity because they were not authorized to talk to the media.
A local tribal elder, Dilawar Khan, confirmed that 13 people were killed in the strike, saying the owner's family was among the dead. He said he did not know the identities of the other people killed or whether there were militants staying at the home, in Data Khel village very close to the Afghan border.
Government officials were not immediately available for comment.
The U.S. is suspected of carrying out more than three dozen such strikes over the past year in Pakistan near the Afghan border. Pakistan says the drone strikes violate the country's sovereignty, kill innocent civilians and generate sympathy for the militants. But the U.S. believes the attacks are an effective tool to combat militants in the region.
Some 700 people in the Orakzai tribal region near the Afghan border protested U.S. missile strikes Saturday, blocking a main road for two hours and chanting anti-American slogans, said a local resident, Azeem Khan.
President Barack Obama has said he will step up the pressure on Pakistan to crack down on militants in its territory by making aid to the country conditional on the government's anti-terrorism efforts. Pakistan has said it is committed to the fight, but many Western officials suspect the country's military intelligence agency of maintaining links with militant groups.
