The checkpoint had been set up because of an intelligence warning that an attack was imminent. — Photo by AP

KABUL: A suicide attacker blew up an explosives-packed car Friday while it was being inspected at a border police checkpoint that had been set up in southern Afghanistan because of a warning of an imminent attack. Three officers were killed.

The explosion happened in Spin Boldak, near the Pakistani border, in the early evening, said Gen. Abdul Raziq, the head of the border police in the south. Three officers and a civilian were wounded, he said.

The checkpoint had been set up because of an intelligence warning that an attack was imminent, provincial government spokesman Zalmai Ayubi said.

In the increasingly violent north, meanwhile, Nato and Afghan forces killed 13 insurgents in an overnight operation targeting local Taliban leaders.

Northern Afghanistan has become more insecure over the past year as insurgents facing pressure from Nato troops in their southern strongholds have pushed into pockets in the north.

The joint raid in Faryab province began late Thursday, said Lal Mohammad Ahmadzai, a spokesman for Afghan police in the north. One police officer was killed in the operation, he said.

NATO said in a statement that the forces were searching for Taliban leaders in Ghormach and Qaisar districts. The coalition did not say whether any of the insurgents targeted in the raid were captured or killed.

In the east, about 45 artillery shells fired from the Pakistani side of the border landed in Dangam district over the course of the day Friday, said provincial police Chief Ewaz Naziri. One child was wounded in the firing, he said, without giving more details.

Tensions have been rising along Afghanistan's eastern border with Pakistan in recent weeks.

Afghan officials have decried shelling from Pakistani territory that has killed an unknown number of civilians, displaced hundreds of people and destroyed several homes and mosques.

Pakistani officials have said previously that the artillery fire was not intentional and said they regretted the killings and damage.

Nato also reported the death of two international service members, one in an insurgent attack in the south and another in an operation in the east. Nato did not provide details. The alliance typically waits for national authorities to release specifics about their casualties.

With the latest deaths, 10 international military personnel have been killed since the beginning of October. So far this year, at least 463 international troops have been killed in Afghanistan.