A Sudanese pastor who was arrested in December has been released. However, another pastor and a Christian activist arrested at the same time are still in detention.

The Rev Kowa Shamal of the Sudan Church of Christ, arrested by Sudan's National Intelligence and Security Service last month, was unconditionally released a few days ago. His colleague, Rev Hassan Abduraheem and Christian activist Talahon Nigosi Kassa Ratta, also arrested last month, are still being held, according to Christian Solidarity Worldwide. "These cases underscore the growing and systematic harassment of Christian religious leaders in Sudan," the charity said.

Both pastors were arrested at their homes. Although family members were given a reason, the pastors were among those who have objected to churches being bulldozed. Shamal's church in Hai Thiba Al Hamyida was demolished in the summer of 2014. Ratta, a member of Sudan Evangelical Presbyterian Church, has campaigned against the confiscation of church buildings.

Christians have suffered growing persecution in Sudan since the secession of South Sudan in July 2011. Sudan is designated a Country of Particular Concern by the US State Department.

The arrests of Shamal and Abduraheem and Mr Ratta were in the same month that Pastor Hafiz Mengisto, senior minister of the Khartoum Bahri Evangelical Church, was tried and acquitted of obstructing a public servant from performing the duties of his office. 

Mervyn Thomas, chief executive of Christian Solidarity Worldwide, said: "Whilst welcoming the unconditional release of Reverend Kwa Shamal, we remain concerned by the continuing incarceration of Reverend Hassan Abduraheem and Talahon Nigosi Kassa Ratta. The arrest and detention of these men are arbitrary and violate their right to liberty and security of person, as articulated in article 9 of the International Covenant on Civil and Political Rights and article six of the African Charter on Human and People's Rights, to which Sudan is a party. We call for their immediate and unconditional release and appeal to the international community, in particular the African Union to hold Sudan to its international obligations."