Afghan National Army (ANA) troops killed 28 insurgents who attacked an security post near the border in the southeastern province of Paktika late Sunday, ministry spokesman Mohammed Zaher Azimi told AFP.

The attack at the Angor Hada post sparked a clash lasting several hours. "Twenty-eight bodies of the enemy were left at the site, four ANA soldiers were wounded and one of the wounded is in critical condition," Azimi added.

The Afghan army seized two Russian-made rocket launchers and 10 rockets.

A second military source said the militants had been able to cross over from Pakistan under the cover of rockets apparently fired from Pakistani territory.

Another three militants were killed after they ambushed a truck transporting supplies for US-led coalition forces in the Sarobi area of the province, he said. A civilian driver was also killed.

"An ANA patrol got to the area. As a result of a heavy exchange of fire, three enemy elements were killed and two of them were arrested with two AK-47 rifles. Two ANA officers were also wounded," Azimi said.

He blamed the attacks on the "enemies of Afghanistan", a term often used for militants linked to the Taliban regime, which was ousted in a US-led campaign in 2001 for failing to surrender al-Qaeda leader Osama bin Laden.

In another attack on Sunday, two Afghan soldiers were wounded in a clash with suspected militants in neighbouring Zabul province, Azimi said.

And on Saturday in southern Kandahar province, three suspected militants were captured, including a local Taliban commander named as Agha Jan, he said. Seventeen AK-47 rifles were also confiscated.

The fighting is the worst since Afghanistan held its first parliamentary elections for three decades on September 18 and highlights the war-wracked country's continuing security problems.

Southern and southeastern Afghanistan have borne the brunt of an insurgency launched by Taliban loyalists to bring the Islamic movement back to power. The unrest has claimed around 1,300 lives so far this year, compared with 850 last year.

On Monday the Nato-led International Security Assistance Force (ISAF) in Afghanistan said NATO's top decision-making body would visit the country this week to discuss plans to expand into the volatile south and probably the east.

ISAF has been in Afghanistan since late 2001 and came under Nato control in 2003. It currently operates in the capital, the north and the west of the country with US-led forces hunting Taliban and al-Qaeda in the south and east.

Most of the bloodshed has been in areas facing Pakistan, prompting accusations by Kabul that Islamabad is failing to curb militants operating from its rugged, lawless tribal areas bordering Afghanistan.