Sudan continues to arrest local Christian pastors on ambiguous and little proven charges, ranging from espionage to undermining national security.

Last week, National Intelligence and Security Services (NISS) re-arrested Rev. Kuwa Shamal, after releasing him in January following his brief detention in December, according to World Watch Monitor.

Shamal, head of Sudan Church of Christ (SCC) missions, was first detained on December 18 but released three days later. He was asked to report to the NISS everyday from 8 am to midnight until January 16. No legal reasons were given for the routine of lengthy interrogation by NISS, which resumed again in February.

Pastor Hassan Abduraheem Taour of SSC was also arrested with Rev. Shamal in December, but has not been released since, and faces charges of "undermining national security." He was even denied access to his lawyer.

This month, NISS released another pastor after detaining him for about six months. Telahoon Nogosi Rata of Khartoum Bahri Evangelical Church was incarcerated on December 13. However, no legal charges were framed against him. Rata was put in prison over suspicions of befriending a foreign missionary.

Under the Sudanese constitution, detainees cannot be held for more than 45 days without trial, but apparently all the regulations were flouted by authorities during periods of pastors' imprisonment.

Since South Sudan separated from Sudan in 2011, its northern neighbour has stepped up its campaign against Christianity. Sudanese President Omar al-Bashir pledged to adopt a strict version of sharia law and only give recognition to Islamic culture after the country's breakup.

In April 2013, government said that it will not give churches licenses to erect new structures, and many of the churches which belonged to South Sudan were razed to the ground.

In June 2015, a group of young women were arrested by Sudan's Sharia police for wearing pants and exposing their arms in dresses. One of the girls was sentenced to 40 lashes. Her lawyers appealed and her case was dismissed by court after an international outcry and lobbying.

The best remembered incidence of persecution against Christians was in 2013. Meriam Ibrahim, a Christian, was arrested for marrying a Christian man, when she was pregnant with her second child. Her father was a Muslim and her mother a Christian. Her father had left her family when she was 6 years old. Sudanese court deemed Ibrahim's marriage as adultery because her father was a Muslim. She was sentenced to 100 lashes and put on a death row, subject to her recanting of her faith. However, she refused to change her faith despite pressure from authorities.

"Faith means life. If you don't have faith, you are not alive," Ibrahim said in an interview in September 2014. She added that faith was her "only weapon" in tough times.