According to Mohabat Christian news agency, authorities entered the newly formed house church meeting in Kermanshah on March 17.

It is not clear why the Christians were arrested but it is suspected that they were detained for their Christian beliefs and participation in church gatherings.

Mohabat News said the Intelligence Ministry agents had used excessive force to arrest the Christians, who were handcuffed and moved to an undisclosed location.

The agents also confiscated Bibles and other Christian material from the house.

Seven of the Christians held were released the following day after signing an affidavit promising not to participate in such meetings.

The rest of the detainees remain in custody. Their families have reportedly been unsuccessful in their attempts to find out about their situation from the authorities.

Mohabat News said an elderly Christian minister, Rev Wilson Issavi, was arrested on February 2 and spent 54 days in detention before being released temporarily from the Dastgerd prison in Isfahan. He is expected to appear before the revolutionary court soon.

Iran has been criticised by human rights groups for its failure to uphold religious freedom.

Last week, Christian Solidarity Worldwide reported that five Christians are to stand trial in a lower court in Iran charged with blasphemy.

There are also grave concerns for Yousef Nadarkhani, the pastor of a large congregation in Rasht, who remains in prison awaiting execution. He is appealing his death sentence for apostasy and a hearing is due to take place in the coming months.