Sixteen security personnel were killed in northwest Pakistan in an attack by Islamist militants early on Saturday, a senior police official in the South Waziristan region said, as Islamist fighters step up their assaults on the security forces.

Another eight personnel were injured in the attack on a security forces post, which took place at 2 am (2100 GMT on Friday), police deputy superintendent Hidayat Ullah told Reuters.

“A search operation is underway in the area,” he added, saying the attackers had used light and heavy weapons.

Tehreek-e-Taliban Pakistan (TTP), also known as the Pakistan Taliban, claimed responsibility for the attack, giving a higher figure for the number of security personnel killed.

“At least 35 security personnel were killed and 15 injured in the attack,” the group said in a WhatsApp channel broadcast. It did not say whether any of its fighters had been killed.

The TTP has carried out more frequent attacks in recent months, mostly targeting members of the security forces.

An umbrella group of various Sunni Islamist militant groups, it has long been fighting in a bid to overthrow the government and replace it with a strict Islamic-led system of governance.

It is separate from the Afghan Taliban movement, but pledges loyalty to the Islamist group that now rules Afghanistan after the withdrawal of US-led international forces in 2021.