Authorities in Vietnam's capital city of Hanoi have kidnapped local activist Truong Van Dung after he refused to come to the city's police to "work" about the Brotherhood for Democracy, an online organization working for promoting human rights and multi-party democracy, local activists said. At 7 AM of Wednesday, Mr. Dung left his private residence in Dong Da district in a bid to join other activists to visit the family of imprisoned pro-democracy activist Phan Kim Khanh. However, Mr. Dung did not come to the meeting with them and they couldn't contact him by phone. Later, his family found that Mr. Dung was detained by police near his house. People living in the area said he was taken by police officers. Mr. Dung, who has actively attended peaceful demonstrations to protest China's violations of the country's sovereignty in the East Sea (South China Sea) as well as government socio-economic policies and human rights abuse, has been summoned by Hanoi police in recent days on relations with the Brotherhood for Democracy, the main target of the ongoing political crackdown, the most severe campaign in decades. In the last ten days, police in Hanoi have harassed Mr. Dung and his family. During APEC Summit held in Danang on November 6-10, police maintained close surveillance over him, sending plainclothes agents to station near his private residence days and nights. Plainclothes agents used iron wire to lock his house door gate during nights. Dung has been beaten many times in the past by plainclothes agents who used iron bars and acid to attack him. He suffered severe injuries from these assaults, including broken ribs. Since late July, Vietnam's authorities have arrested seven key members of the Brotherhood for Democracy on allegation of subversion under Article 79 of the country's 1999 Penal Code. Police also added subversion charges on its founder Nguyen Van Dai and his assistant Le Thu Ha, who were detained in late 2015 with an initial allegation of conducting anti-state propaganda under Article 88 of the Penal Code. In addition, police have also summoned many members of the Brotherhood for Democracy for interrogation. Among them are bloggers Nguyen Tuong Thuy and Le Anh Hung, and former prisoner of conscience Vu Van Hung. In order to maintain the country under a one-party regime, the Communist Party of Vietnam has ordered the government to make all efforts to prevent the formation of opposition party and it sees the Brotherhood for Democracy as a potential political threat. Other activists have also been persecuted by the government. Since the beginning of this year, Vietnam has arrested, sentenced or expelled 25 activists who exercise their basic rights enshrined in the country's 2013 Constitution.