PESHAWAR: A teen suicide bomber in a school uniform attacked soldiers during morning exercises at a Pakistani army training camp Thursday, killing 30 troops and wounding 40 others, police and the military said, DawnNews reported.

The attack in the northwest town of Mardan showed that despite years of army operations against their hideouts along Pakistan’s border with Afghanistan, Taliban and al Qaeda-linked fighters retain the ability to strike back. It was one of the worst attacks on security forces in recent months.

Senior police official Abdullah Khan earlier told AP that 27 soldiers died and around 40 were wounded, some critically. Khan said an examination of the body parts at the scene indicated the bomber was a teenage boy, which is a common finding in suicide bombings in Pakistan.

The army, which tends to release information much slower, put the death toll in an earlier statement at 20 and confirmed the general circumstances.

Despite his apparent disguise, the bomber’s ability to get his explosives into the facility undetected signaled a failure on the part of the military. Such army areas are usually heavily guarded, though an attack on the same training facility in 2006 killed 35 soldiers.

Troops quickly cordoned off the area and even police had a difficult time getting through.

No particular militant group immediately claimed responsibility Thursday, though the Pakistani Taliban have staged such attacks in the past.

The army has staged multiple offensives in Pakistan’s northwest aimed at taking out the Pakistani Taliban in recent years. Its efforts against the group, which is distinct from but linked to the Afghan Taliban, appear to have been largely successful — but violence persists.

The US has encouraged Pakistan to eliminate the Pakistani Taliban in the belief that the long-term stability of the nuclear-armed Muslim nation is critical to global security.

Washington also wants Islamabad to take out militants who focus on fighting the US and Nato in Afghanistan but who have bases on Pakistani soil, in particular in the North Waziristan tribal region. But Pakistan has yet to mount an offensive in that area.

In North Waziristan on Thursday, the bullet-riddled bodies of two tribal police officials and a villager were discovered along an open road near the town of Mir Ali, a militant stronghold. A note attacked to the bodies accused them of acting as spies for the US, resident Asif Iqbal said.

Intelligence officials said the three men had been kidnapped in January. Their bodies showed signs of torture, the officials said, speaking on condition of anonymity because they were not authorized to speak to media.

Militants have killed numerous North Waziristan residents after accusing them of spying. The killings are often linked to allegations that local residents are providing intelligence on militants that helps the US launch missile strikes in the area.