A roadside bomb killed five Afghan border security guards traveling on a heavily used road in southern Afghanistan near the border with Pakistan on Sunday.
Gen. Abdul Raziq, a border security commander, said the bombing occurred before dawn in the Spin Boldak district of Kandahar province. The Ministry of Interior said the explosive struck an Afghan National Police vehicle, killing the five.
The attack comes amid reports that nearly a dozen militants suspected of having ties to high-ranking Taliban members were detained in separate operations Sunday, underlining the security struggle in the country's south.
The district is in a volatile area that has been patrolled mostly by border security police. U.S. troops moved into the region in July.
Meanwhile, NATO said in a statement that forces detained several militants with links to the Taliban on Sunday.
Several people were detained in Kandahar province, including a suspected militant who NATO says was involved with suicide bombings in the area and has links to several senior local Taliban leaders.
South of Kabul, an Afghan-international security force detained several militants near the village of Kashimiri Balat while pursuing an alleged Taliban member involved in the weapons trade, it said. The joint security force recovered a number of weapons, including grenades and a military-grade night vision device.
In another operation south of the capital, a joint force detained several suspected militants, including a Taliban commander linked with several local Taliban leaders.
Also, in Ghazni province on Sunday, a joint force killed a militant, detained another and recovered pistols and grenades while pursing a Taliban commander.