No one claimed responsibility for the attack on Monday in North Waziristan, a district in the Khyber Pakhtunkhwa province that borders Afghanistan. A military statement said four soldiers were martyred in the attack and that an investigation was underway.

The attack came a day after a late night roadside bombing in eastern Afghanistan struck a vehicle carrying members of the Pakistani Taliban, killing a senior leader and three other militants traveling with him.

The Pakistani Taliban blamed intelligence agents for the high-profile killing on Sunday night, without offering evidence or elaborating.

Tehreek-e-Taliban (TTP) said an announcement would be made regarding "the martyrdom of a central leader".

The slain leader of the Pakistani Taliban, the Tehrik-e-Taliban Pakistan or TTP, was Abdul Wali, also widely known as Omar Khalid Khurasani.

Khurasani's death was a heavy blow to the TTP, which is in talks with the Pakistani government amid an ongoing cease-fire, announced in May. Isolated militant attacks have continued, though the TTP has not claimed responsibility for any of them since the truce first went into effect. The talks are being hosted by the Afghan Taliban.

His death may bring an end to a shaky indefinite ceasefire the TTP reached with the Pakistan government in June as peace talks mediated by Afghanistan's Taliban progressed.

North Waziristan and other former tribal regions in northwestern Pakistan were long a base for the Pakistani Taliban and other militant groups until the army claimed a few years back that it cleared the region of insurgents. Occasional attacks have continued, however, raising concerns the Pakistani Taliban are regrouping in the areas.

The Pakistani Taliban are a separate group but allies of the Afghan Taliban, who seized power in Afghanistan a year ago as the U.S. and NATO troops were in the final stages of their pullout.

The Taliban takeover in Afghanistan has emboldened the Pakistani Taliban to intensify their demands for stricter enforcement of Islamic laws in Pakistan, release of their members from government custody, and a reduction of military presence in Pakistan's former tribal regions.

Kabul insists it will not allow Afghan soil to be used by militant groups plotting against its neighbours.

Last week, President Joe Biden announced Al-Qaeda chief Ayman al-Zawahiri was assassinated in a US drone strike in Kabul, calling into question the Taliban's promise not to harbour militant groups.

The Taliban later issued a carefully phrased statement that neither confirmed Zawahiri's presence in Afghanistan nor acknowledged his death.

The peace talks have angered many in Pakistan, who remember brutal attacks by the TTP -- including on schools, hotels, churches and markets.