The families of the pastors on trial and facing the death sentence in Sudan have been allowed to visit them in prison.
Prosecutors of Pastors Hassan Abduraheem, Kuwa Shamal and Darfuri student Abdulmonem Abdumawla have been demanding the harshest possible penalties which could mean capital punishment on some of the charges against them.
The are accused of at least seven crimes, including waging war against the state and spying. Petr Jasek, a Czech aid worker, is also on trial.
The case against Abduraheem and Abdumawla appears to revolve around a request for assistance with medical costs from a young Darfuri man who was injured during a demonstration.
"His friend Mr Abdumawla began collecting funds towards his medical expenses from various organisations and individuals. Through a colleague, Mr Abdumawla was put in contact with Reverend Abduraheem, who donated money towards Mr Omer's treatment. The case against Reverend Shamal appears to be related to his friendship with Reverend Abduraheem and his senior position in the Sudan Church of Christ," reported Christian Solidarity Worldwide (CSW).
The charges are of intelligence activities and providing material support for rebels in the war-torn country.
Open Doors reported that the prosecutors have demanded the harshest possible punishment for the pastors, whch could mean a death sentence.
CSW's chief executive Mervyn Thomas said: "These men have committed no crime. Rev Abduraheem and Mr Abdumawla responded with compassion to a request for medical assistance and Rev Shamal's only connection to this case is his friendship with Rev Abduraheem and his senior position as a church leader.
"We urge the government to end the harassment and targeting of religious and ethnic minorities by the security services, as has clearly occurred in this case, and to uphold the civil rights of all Sudanese citizens.
"While commending the decision to allow these men to receive visits from their families and legal representatives, we call on the government to ensure this access continues for the duration of the trial in keeping with fair trial principles."
Video of a hymn-singing protest outside the courtroom in Khartoum, Sudan posted on Facebook by Youeel Ibrahim.
