Thirteen Christians were reportedly tortured by authorities in Sudan, leaving one vomiting and bleeding in critical condition, before they were released on Monday.
The Christians that were tortured include the 12 that were arrested by the Sudan National Intelligence and Security Services in Darfur earlier in October, along with church leader Tajaldin Idriss Yousif.
Morning Star News reported that the Yousif was released on Monday, while the 12 others were let go a day before.
"All of them were said to be tortured by NISS and are in bad shape," a source told the persecution monitoring group.
"One of them is said to be in critical condition owing to torture. He is said to have been vomiting and bleeding. He was rushed to a hospital, but he was not attended to by the physicians in that hospital," the source added.
The Christians were originally handcuffed and arrested for interacting with Muslims in the predominantly Islamic region, International Christian Concern said.
"The arrests were done at Nyala market while the young men were interacting with Islam adherents, building rapport for witnessing, when Sudan's security authorities surrounded them and led them to the police station, handcuffed," said at the time ICC's source, the Rev. Kuwa Shamal.
"Some of the arrested men are disciples that I baptized in 2015 when they left Islam and converted to Christianity. The detainees have been doing a recommendable work of sharing the Good News in Darfur, and we pray for their immediate and unconditional release," Kuwa added.
The Christians were subjected to two weeks of jail and interrogation, without being taken to court. Several of those identified are reportedly members of Yousif's church.
Christians in Sudan began facing increased persecution since the country split apart from South Sudan in 2011, and President Omar al-Bashir set a course for adapting a stricter version of Sharia law.
Believers have been arrested and released on a number of occasions this past year. A court struck down criminal charges against a group of Christian leaders in August, who had said that the government was trying to take away their denominational control.
The eight Sudanese Church of Christ leaders, including the elected president, had refused to give up control of the predominantly Nuban denomination.
"This case demonstrates the politicization of the criminal justice system, resulting in religious leaders, who are upstanding members of the community, being forced to defend themselves against unwarranted criminal charges," said at the time Christian Solidarity Worldwide Chief Executive Mervyn Thomas.
Open Doors USA has meanwhile warned that Christians in Sudan are losing churches in which they have have worshiped in for years.
"The government regularly arrests and intimidates Christian leaders and has demanded on at least one occasion that leadership be handed over to a government-supported committee. When interacting with Sudanese Muslims, Christians must be extremely cautious, as any mention of their faith can be construed as an 'act that encourages apostasy against Islam,'" the watchdog group has said.