The United States has warned Americans in Afghanistan, especially American journalists and foreigners working for U.S. media groups, that they may be targeted for kidnap. The warning comes as suspected Taleban insurgents are said to have abducted Friday, two vehicles from a U.N. funded aid group.

The State Department says the U.S. embassy in Kabul has received "credible information" that remnants of the ousted Taleban government may try to take American journalists hostage, to exchange for Taleban members in U.S. custody.

The warning comes amid increased reports of anti-government activities led by the Taleban and guerrillas of the al-Qaida terror network, particularly in the southern and eastern parts of Afghanistan.

The warning also coincides with increased concerns over new terrorist attacks in the United States and in Saudi Arabia.

A U.S. military spokesman said Saturday that a group of militants fired rockets at U.S.-led coalition forces in Afghanistan's northeastern border province of Kunar. He said the coalition soldiers responded with small-arms and aerial fire, and the soldiers suffered no casualties.

On Friday, Taleban insurgents reportedly hijacked two vehicles of a U.N. funded organization capturing their drivers and communication equipment in the southern province of Zabul, where a Turkish engineer was kidnapped last week. The engineer's captors have demanded the release of Taleban prisoners in return for his release, but Afghan authorities have so far refused to make such a deal.

Recent reports have also quoted fugitive Taleban officials as threatening to kill taxi drivers and other Afghans if they work with foreigners.

Maj. Kevin Arata, a spokesman for the NATO-led International Security Assistance Force, known as I-SAF, says security remains a major problem in Afghanistan.

"We regard that the situation over here is a dangerous one and that we are doing all we can to help lessen the problems that do exist," he said. "We have made progress on several fronts with regard to capturing people that are doing bad things over here."

The multinational force is still largely confined to the capital, Kabul. The U.N. Security Council recently mandated the peacekeepers to expand their operations to other parts of Afghanistan, but only Germany of the I-SAF countries has allowed its troops to be deployed outside the capital.