Eighteen of the alleged militants died early Friday at a military checkpoint in the Orakzai tribal region.

Lt. Col. Tahir Akram, a spokesman for the paramilitary Frontier Corps, said the fighting involved insurgents who arrived from the nearby Khyber region to try to retake the checkpoint in Orakzai where the Taleban have a heavy presence. He said the security forces repulsed the attack and captured four insurgents. One soldier was wounded. The violence was concentrated in the districts of Orakzai, where the military has been waging a nearly three-week offensive against the Taleban, and Kurram, which has a tradition of sectarian unrest and Islamist militancy.

The military has announced a running death toll of more than 100 militants in the Orakzai operation since March 24, but the figures cannot be verified independently because access to the remote area is extremely limited.

Orakzai is a former bastion of Tehreek-e-Taleban Pakistan leader Hakimullah Mehsud, whom US officials believe probably died in a US drone attack in January. The Pakistani military says it has no evidence he is in the area.

Close to the tribal belt, police said they killed two suspected would-be suicide bombers after a gunfight in northwestern Lakki Marwat district, where a massive bomb attack killed 101 people on New Year’s Day.

“Two suspected suicide bombers, when chased and confronted by police, hurled a hand grenade at them and then a gunfight lasting about 40 minutes started,” district police chief Muhammad Ayub.

“Both suicide bombers were killed by police,” Ayub said. He described both as younger than 25 years old and residents of Lakki Marwat.

Under US pressure, Pakistan has in the past year significantly increased operations against militants in its tribal belt, which Washington has called the most dangerous region on Earth and a global headquarters of Al-Qaeda.

The rugged tribal terrain became a stronghold for hundreds of extremists who fled neighboring Afghanistan after the US-led invasion in late 2001.

Washington says the militants use Pakistan’s semi-autonomous tribal belt to plot and stage attacks against NATO troops stationed in Afghanistan.