TWO evangelists and a church leader were arrested last month by Public Security Bureau officials in the southwestern city of Guilin, in an apparent crackdown on unregistered Protestant activities, the religious agency News Network International reported. Quoting Hong Kong sources who recently returned from the region, the agency said several illegal house churches had also been closed down. The agency said security officials arrested the itinerant evangelists - a man and a woman in their 20s, both from Fangcheng, Henan - after raiding a house church where they were living. The leader of that unregistered church was also arrested during the raid. The three were reportedly interrogated at the Public Security Bureau's Guilin headquarters and remain in police detention. It is not known if charges have been filed. Following the raid, security officers placed the house under surveillance, later arresting two other unregistered Christians as they entered the premises. The two Christians were briefly interrogated about their association with the church. Sources in Guilin said security officials raided at least four other house churches last month, ordering them closed and placing them under police surveillance. Several key house church leaders have since fled the city. Some Guilin church members alleged the recent escalation in police detention followed actions by leaders of Guilin's state-sanctioned Protestant Three-Self Patriotic Movement to highlight the illegality of the house churches. And according to Hong Kong sources, at least seven key house church leaders from Fengcheng had fled their homes last month fearing prosecution. In a separate development, the widow of a mainland Christian who was beaten to death in a police cell early this year has been repeatedly harassed by security officials and kept under tight police surveillance. Sources said security officials had interrogated Yin Dongxiu numerous times since May, after she filed a suit against local police and the Public Security Bureau, whom she blamed for the death of her husband, Zheng Musheng. Meanwhile, the international human rights organisation Amnesty International has issued an appeal on behalf of a university professor belonging to China's Mongolian minority it says is imprisoned for political reasons. Ulaanshuvu, a former lecturer at Inner Mongolia University, is suffering from heart, kidney and other health problems that have grown worse during three years of detention, Amnesty said. The group said Ulaanshuvu had been denied adequate medical care and food and subjected to verbal and physical abuse as well as long periods of interrogation. He was detained in 1991 and was sentenced to five years in prison in April this year for having participated in pro-democracy activities in 1989, Amnesty said.