The fighting erupted Thursday after insurgents attacked an Afghan Army convoy on a main highway, The New York Times reported, quoting Afghan officials. Five militants were captured.

NATO Secretary-General Jaap de Hoop Scheffer, concerned about growing violence in the country and against NATO-led forces, said the foreign fighters and terrorists want to destabilize Afghanistan as they have done in neighboring Pakistan and other parts of the world, The Times report said.

He called for a regional political approach to the danger, saying, "I cannot imagine anyone who would consider it acceptable that many terrorists from all over the world gather in a certain area and create mischief and havoc there."

Afghan and Western officials have also warned of increasing numbers of foreign fighters and trainers reaching Pakistan's tribal areas to mount attacks across the border into Afghanistan. A Western official told The Times the outsiders included Arabs, Turks, Chechens, Central Asians and Pakistanis, some of whom have been killed or captured.

Afghan President Hamid Karzai says the country will not be safe "unless Afghanistan and the international community address the question of sanctuaries in Pakistan, and the terrorist training camps there."