The father of an American aid worker being held by Afghanistan's ruling Taleban movement on charges of preaching Christianity says his jailed daughter is living in fear of being trapped by a possible U.S. military attack.

Taleban religious police arrested two American women, Heather Mercer and Dayna Curry, along with six other foreign aid workers in early August, accusing them of converting Muslims to Christianity. The Taleban Supreme Court in Kabul is trying the foreigners from the German-based relief agency, Shelter Now.

John Mercer, the father of 24-year-old Heather Mercer, told reporters in neighboring Pakistan that he and his wife, Deborah Oddy, are trying to travel to Afghanistan to be with their daughter, who is sick with fear.

"I think after 63 days [in jail], she is wearing down and she has been very upset," he said. "She is very frightened. They can hear almost nightly the mortars going off, the rockets. This is frightening her quite a bit and she knows about what happened in the U.S. and she is afraid that bombs are going to start falling on Kabul."

The United States is preparing possible attacks against the Taleban for refusing to hand over Osama bin Laden, a prime suspect in last month's terror attacks in New York and Washington.

Mr. Mercer and his wife Deborah Oddy say they have been regularly corresponding with their daughter by fax messages through the Taleban foreign ministry in Kabul. The Pakistani lawyer for the eight detainees, Atif Ali Khan, said on Thursday that the Taleban court is expected to pass light sentences on the basis of compassion. Ms. Oddy says she hopes their lawyer's impression would prove correct. "We don't know if that is his feeling, or if he has actually had hard facts on that. Right now, we are all thinking it is his feeling, and it is our hope that this feeling is correct," she said.

John Mercer says he is confident that the Taleban will not use the detained aid workers as "pawns" in case they come under an attack from the United States. "Their religion, Islam, is a very humane, very just religion and for them to use these detainees as pawns would certainly in my opinion would not rest well with the rest of the Muslim world. So I don't think that they would be doing that intentionally," he said.

Four Germans and two Australians are among those being tried for spreading Christianity in Afghanistan. The Islamic Taleban has banned the practice in areas under its control. Sixteen Afghan workers of the Shelter Now aid agency have also been detained. They will be tried separately at a later date and could be sentenced to death under the Taleban's interpretation of Islamic law.

The parents of Heather Mercer, along with diplomats from Germany, the United States, and Australia saw the detainees in Kabul. But they left Afghanistan after the terror attacks in the United States prompted fears of U.S. strikes on the Taleban.