Taleban Foreign Minister Wakil Ahmed Motewakel had said the foreigners would appear in court during the "second phase" of the trial and diplomats, relatives and journalists would also be allowed to attend.

American, Australian and German diplomats as well as parents of two female American aid workers of the German-based Shelter Now International (SNI) were present at the audience, but journalists were not allowed in.

Under Islamic laws of Shari’a that forbid any proselytising in Muslim land, even by recognised religions such as Christianity and Judaism, the accused could face execution.

The Taleban have said that the Afghan aid workers will be tried at a later date.

"The same penalty will be applicable to the Afghans who converted from Islam to Christianity if they refuse to come back to Islam", journalists quoted Taleban sources as having said.

Sources say Shelter Now International is in fact a missionary organisation which had problems of the same nature with Pakistan authorities in the past.

"I am hearing a case against foreigners who are accused of spreading Christianity. Let me tell you that they are just accused of this. We will not do any injustice to them", Saqeb assured, adding: "We will give punishment to the accused according to Islamic laws, be that imprisonment or hanging. If they have broken the law and deserve hanging, we will punish them in that way."

"The evidence that has been seized includes hundreds of Bibles translated into Dari and Pashto languages which were being used to teach and preach Christianity in Afghanistan", he told worshippers during the Friday preaching.

One of the detainees, Georg Taubmann, launched a strongly worded attack on the investigation against them, telling Saqeb that they have never been informed of the charges against them nor why they have been detained or done wrong?"

A BBC correspondent quoted Mr. Taubman, the Director of SNI, as having also complained that the prisoners had been cut off from the outside world, with no contact allowed with their families.

"We have never converted anybody. We are shocked with the accusations", he told judges in the Supreme Court.

Earlier, reporters in Kabol watched the defendants led through the gate of the Supreme Court building in tight security.

Eyewitnesses said they looked exhausted and walked slowly into the court under the escort of armed guards, who did not allow them to answer questions from waiting journalists.

It is the first time foreigners have been charged with preaching Christianity in Afghanistan.

Some 15 donor countries in the Afghan Support Group (ASG) said they were "very concerned" at the aid workers' detention and the Taleban's closure of two Christian relief groups last week.

"Donor countries are dismayed at the constant deterioration of working conditions for the aid community".

French foreign ministry spokesman Francois Rivasseau said in Paris the Taliban was guilty of "growing hostility" toward relief organisations despite a humanitarian crisis in the country.

United Nations special envoy to Afghanistan Francesc Vendrell on Thursday met Taleban Deputy Foreign Minister Abdul Jalil and requested the prisoners be allowed more frequent visits from doctors and relatives, UN officials said.

Erick de Mul, the head of the mission, said: "I told the Taleban: If you want to fight the whole world, if you want to fight with 184 member states of the UN, that's your choice, but don't expect us to do that.

"There are conditions under which we can operate and if they're not acceptable to them, then we'll have to close down", he said, as the already tense relationship between the Taleban and the aid community on which the country depends has grown increasingly worse in the last month.

Humanitarian aid workers said it was no longer safe for them to walk on the streets and aid agencies have been prevented from reaching thousands of starving refugees in the Hazarajat region of central Afghanistan.

The final straw, though, for the UN has been the Taleban's refusal to allow a long-overdue survey of poor households for the bread distribution programme.

These include those headed by thousands of war widows whom the Taleban have forcibly prevented from earning a living.

The IEA have banned men from entering non-family households where women might be present, so only women can carry out the survey.

But as women are not allowed to work anywhere other than in a hospital, they, too, are effectively banned from conducting the survey.

First they ordered Afghanistan's tiny Hindu and Sikh population to wear yellow identity tags.

Then, two weeks ago, about 20 religious police, brandishing Kalashnikovs, forced their way into a newly opened 100-bed hospital for war victims and accused the male and female staff of having lunch together and talking to each other.

If the UN and other agencies end all or even some of their programmes in Afghanistan, the result will be catastrophic.

Last year government and non-government aid agencies spent some a total of £420,000 daily in Afghanistan and the amount is expected to rise to £560,000 this year.

About 600,000 refugees are on the brink of starvation.

The official, who asked not to be named, said that his country had received several requests, through diplomatic channels and direct contacts with senior officials, to intervene with the IEA to release the detained Westerners, but had turned down all these requests.

"Saudi Arabia severed relations with the Taleban several years ago for adopting a pro-terrorism policy and hosting a number of terrorists led by (the Saudi millionaire anti-American crusader) Osama bin Laden", he said, adding that the Taleban "still refuses to abandon this policy".

Mr. Bin Laden is Washington’s most wanted man, accused of twin bombing of American embassies in Kenya and Tanzania, but the Taleban refuses to hand him over to the United States.

The official branded the detainees as "enemies of Islam and Muslims" as they had gone to Afghanistan, which is a Muslim country, to "urge its citizens to convert from Islam and embrace Christianity, and exploited the poverty prevailing there".