Six other troopers were wounded in the attack in the Barakhel area of Dera Ismail Khan, a settled district adjoining the restive tribal region of South Waziristan on the border with Afghanistan.

"The car has been totally destroyed. I can see some three to four military vehicles at the spot. The army has cordoned off the area and is not allowing anyone near," a Reuters' journalist said.

"An army convoy was on its way near Tank, when a suicide bomber rammed his car into the convoy, destroying one car and killing two soldiers," said army spokesman Major-GeneralShaukat Sultan.

North and South Waziristan are regarded as hotbeds of support for al-Qaeda and Taliban, and peace deals struck with the government in both regions are hanging by a thread following an army airstrike on a militant base last month.