A suicide bomber attacked a military convoy in a Pakistani tribal region along the Afghan border, killing four soldiers, the army said on Tuesday.
The incident took place in Mir Ali, North Waziristan district, according to an army statement.
Police and intelligence officials told Reuters the bomber rammed a three-wheeler into the convoy late on Monday in the remote district, which has seen a rise in militant violence in recent weeks.
The region was once a hotbed of local and foreign Islamist militants but they have mostly been driven out by various Pakistani military operations.
No one has claimed the responsibility for the bombing, which came a day after a senior Pakistani militant with a $3 million US bounty on his head, Abdul Wali, also known as Omar Khalid Khurasani, was killed in an explosion in Afghanistan.
Khurasani's Jamat-ul-Ahrar (JuA), designated as a terrorist group by the United States and the United Nations, had claimed responsibility for multiple attacks against police, military, minority Shiite Muslims and Christians, which killed hundreds of people in Pakistan.
Tehreek-e-Taliban Pakistan (TTP), also known as the Pakistani Taliban, an umbrella group of Sunni militant groups which includes the JuA, confirmed Khurasani's death.
Khurasani along with three other commanders was killed in an "enemy attack", the TTP said in a statement sent to Reuters without giving mode of the attack or the place of its happening.
The TTP wants to overthrow the Pakistani government to govern it under a harsh version of Sharia law.