Concerns have been raised about the welfare of residents at a Coptic Christian monastery in Sudan after it was taken over by members of a special military unit with a poor human rights track record.

The members of the Rapid Support Forces (RSF) have been using the monastery in Wad Madani as a military base since 16 December. 

The RSF were formerly under the control of the Sudanese government but since April this year they have been fighting against the Sudanese Armed Forces (SAF) and have been declared a rebel group. 

Christian Solidarity Worldwide (CSW) reports that video footage was released by the RSF showing the monastery's residents being harassed. At least five priests, five trainee priests and four labourers remain missing.

CSW's Founder President Mervyn Thomas said: "CSW is highly concerned by the attack on the Coptic monastery in Wad Madani, and particularly, for the wellbeing of those whose whereabouts remain unknown." 

He expressed concern about reports of serious human rights violations in areas under RSF control, and called for a ceasefire with the SAF as well as international intervention. 

"We call on all warring parties to conclude a full and comprehensive ceasefire, and to immediately end the escalation in human rights violations which may amount to atrocity crimes," he said.

"The international community must also take extensive action to ensure that those responsible for egregious violations against Sudanese citizens, both during this conflict and before it, are held to account, and to penalise any nation or entity that is effectively aiding and abetting the commission of war crimes and prolonging the suffering of civilians by funding or arming the belligerents."