At least ten people were killed in a roadside bomb that targeted a minibus in Pakistan’s remote northwestern tribal region bordering Afghanistan, an official in the region said.

Shahid Ali Khan, a senior regional Pakistani official, told Reuters militants planted a roadside bomb in the Kurram Agency in the Federally Administered Tribal Areas (FATA).

The breakaway Taliban faction of Jamat-ul-Ahrar said it was behind the attack

“When the passengers were coming, they detonated the remote-controlled bomb,” said Khan, who is the assistant political agent for Kurram Agency in FATA, which borders Afghanistan.

A woman and two children were among the nine killed while 13 people were wounded in the explosion. With few adequate medical facilities in the area, a Pakistani army helicopter evacuated the wounded to a nearby military hospital.

Prime Minister Nawaz Sharif’s office said the premier had “directed relevant authorities to extend maximum support for treatment of the injured”.

Parachinar and the surrounding area has suffered sectarian tension between Sunni and Shi’ite Muslims in the past.

Several major attacks have rocked the Kurram Agency area this year, including a bomb blast at a mosque that killed more than 20 people in March in Parachinar.

Also Tuesday, four convicted members of the Pakistani Taliban were executed in a prison, the army said.

In the southern port city of Karachi, paramilitary forces raided an apartment following a tip that militants were hiding there, police officer Aurangzeb Khattak said.

After a seven-hour siege, three militants, including a woman, blew themselves up inside the apartment. The explosion also killed a 5-year-old while a fourth militant was killed trying to flee the scene.