Eight foreign aid workers charged with preaching Christianity went on trial in Afghanistan Tuesday, officials from the Taliban government said.

The workers, which include two young American women, were arrested four weeks ago on charges of spreading Christianity in the devoutly Muslim nation. Chief Justice Noor Mohammed Saqib said the trial would be closed, despite earlier promises that the proceedings would be open to the families of the accused and journalists. The trial is expected to last several days.

The accused workers belong to the German-based group Shelter Now International, an anti-poverty organization. While the group is Christian, it has denied that the workers were proselytizing. However, the radical Taliban militia that controls Afghanistan imposes an extreme form of Islam on the impoverished South Asian nation and claims the aid workers were trying to convert Muslims to Christianity.

Saqib and 14 bearded Islamic clerics met for nearly four hours Tuesday at the start of the trial, which will eventually allow the eight foreign aid workers to speak in their own defense.

Saqib would not say when they would be called to the court. He said they would also be provided a lawyer if they requested one.

The eight foreign aid workers, who also include four Germans and two Australians, were arrested along with 16 Afghan staff members. The foreign aid workers, to be tried separately from the Afghan staff, face penalties of jail and expulsion. The Afghan workers face the death penalty for teaching Christianity.

The ordeal has been a nightmare for the parents of the two jailed Americans, Dayna Curry, 29, and Heather Mercer, 24.

On Monday, John Mercer of Vienna, Va., celebrated his birthday quietly while waiting at the United Nations guest house for news about his daughter's fate.

"The only present I want is to have my daughter home," he said.

Curry's mother, Nancy Cassell, a teacher from Thompson's Station, Tenn., took comfort in the hope that the ordeal would soon be over.

Three Western diplomats from Germany, Australia and the United States have tried to get information about the legal procedure under Taliban rule, but have been unsuccessful.

Saqib said Tuesday he was willing to explain the procedure to the diplomats if they wanted to come to the court and meet him.

The only precedent of a foreigner being tried in Afghanistan under the Taliban occurred in March 1997, when two French employees of the Paris-based Action Contre la Faim were tried on charges of immoral conduct.

Facing litigation after spending 26 days in a Taliban jail, they were sentenced to time served and ordered to leave the country immediately. Their trial lasted less than one hour.

The charges against the two French nationals were made after their humanitarian aid organization held a lunch for Afghan women employees during which Afghan men were also in attendance, a crime under Taliban law.

The Taliban impose strict segregation of the sexes among Afghan men and women. Afghan women are required to wear the all-encompassing burqa, which hides them from head to toe. They are not allowed to work, attend school after the age of 8, or travel without a male relative.

Afghan men must wear a beard and cover their heads. Male government employees have to wear a turban.

The Taliban's strict enforcement of their laws among Afghans has left many international aid organizations fearful for their local employees.

A senior Taliban official has told The Associated Press that at least some of the 16 employees — probably the teachers — will be either sentenced to life in jail or death by hanging.

One of the books the Taliban say they have confiscated from Shelter Now International in Afghanistan was entitled Sharing Your Christian Faith With Muslims, which the ruling militia considered to be a book about proselytizing.

Known as a missionary organization among expatriate workers in Afghanistan, Shelter Now International was forced to close in neighboring Pakistan during the early 1990s after its employees were said to be proselytizing in Afghan refugee camps.

The other six foreign aid workers being held have been identified by the Taliban as Germans George Taubmann, Margrit Stebnar, Kati Jelinek and Silke Duerrkopf, and Australians Peter Bunch and Diana Thomas.

The Associated Press contributed to the report.