Militants attacked a military post in Pakistan near Afghanistan on Saturday morning using a vehicle laden with explosives, killing five security force members, Pakistan’s military said.

The incident in northwest Pakistan was carried out by six attackers, the military’s media wing said in a statement, without naming the militant group responsible for the attack.

“The terrorists rammed an explosive laden vehicle into the post, followed by multiple suicide bombing attacks, which led to collapse of portion of a building, resulting into Shahadat (martyrdom) of five,” the statement said.

Residents in Waziristan, an area bordering Afghanistan in Pakistan’s Khyber Pakhtunkhwa province, told Reuters an explosion shook doors and damaged windows around the time of the start of the attack.

Pakistani government and security officials say attacks have risen in recent months, many of them claimed by the Pakistani Taliban (TTP). Officials say militants are using Afghan soil to launch attacks.

That has damaged the relationship between Pakistan and the ruling Afghan Taliban, who deny allowing Afghanistan to be used by militants.

Pakistan’s national elections in February took place under tight security. Nine people died in blasts, grenade and gun attacks on election day.