The State Department in Washington said on Friday that remnants of the Taliban militia are planning to abduct American journalists in an attempt to win the release of their compatriots currently held by the US.
The statement issued through the US embassy in Kabul said journalists should "take immediate steps" to increase their personal security.
"The United States Embassy in Kabul has received credible information that Taliban forces are actively searching for American journalists to take hostage for use as leverage for the release of Taliban currently under United States control," it said.
"American journalists in Afghanistan are urged to take immediate steps to increase their security posture in light of these threats," the embassy said in a notice to US citizens in the country.
The notice, a copy of which was provided to AFP in Washington by the State Department, did not elaborate on the threat. The United States is holding an undisclosed number of Afghans and foreign fighters picked up in Afghanistan and elsewhere whom it deems "enemy combatants" at its naval base in Guantanamo Bay, Cuba.
The alert followed a new spate of security alerts and threats in the Afghan capital, which is under the protection of a NATO-led security force.
Journalist Daniel Pearl was
kidnapped and killed in Pakistan
US journalist Daniel Pearl, the Wall Street Journal's South Asia
bureau chief, was abducted and killed in Pakistan last year.
Other US journalists and citizens have been kidnapped in the past by groups trying to put pressure on Washington, notably during Lebanon's civil war.
US forces are battling, alongside Afghan government troops, what its commanders say are reconstituted elements of the ousted Taliban regime as well as remnants of al-Qaida.