DERA ISMAIL KHAN, Pakistan (AP) — A roadside bomb targeting a police vehicle killed six officers in northwestern Pakistan near the Afghan border on Monday, police said, underscoring a surge in militant violence in the region.

The blast struck in Tank district of Khyber Pakhtunkhwa province, local police chief Pervez Shah said. The dead included a local police chief, Ishaq Ahmad, who was on routine patrol at the time of the attack. Shah provided no further details, saying an investigation was underway.

Pakistan’s Interior Minister Mohsin Naqvi condemned the attack and paid tribute to the killed officers. In a statement, he offered his condolences to the families of the victims, saying the officers had “sacrificed their lives for the nation’s peace and that their sacrifices would not be forgotten.”

No group immediately claimed responsibility. Suspicion is likely to fall on the Pakistani Taliban, known as Tehrik-e-Taliban Pakistan, which has intensified attacks on security forces and civilians in recent months.

The TTP is separate from but allied with Afghanistan’s Taliban rulers and has been emboldened since the Afghan Taliban returned to power in 2021. Pakistan has accused Kabul of allowing the group to use Afghan soil to launch attacks inside Pakistan, a charge the Afghan government denies.

Relations between the two neighbors have remained strained. Tensions escalated in October after Kabul accused Islamabad of carrying out a drone strike in the Afghan capital. Subsequent cross-border clashes killed dozens before Qatar brokered a ceasefire on Oct. 19.

The truce remains in place, though recent talks between the sides in Istanbul ended without progress.