Vietnamese authorities have ramped up their harassment of dissident rights lawyer and former political prisoner Nguyen Bac Truyen, stationing a large group of security agents in plain clothes outside his rented house on Wednesday 5th November and threatening his landlady with a knife, according to sources. Truyen, who provides free legal assistance to victims of land grabs and has campaigned for multiparty democracy in one-party communist Vietnam, was released on probation from prison in May 2010 after serving three and a half years for "conducting propaganda against the state." He now lives in a house in southern Vietnam's Ho Chi Minh City rented from another former prisoner, Pham Minh Hoang, a blogger and former mathematics teacher serving a period of probation after his own release from prison in January 2012. "To them[the police], Nguyen Bac Truyen is a very dangerous man, so they guard him all the time," Hoang told RFA's Vietnamese Service on Wednesday. "They have assigned people to sit in front of the house and block him from leaving," Hoang said. "They sit in front of that house 24 hours a day," Hoang's wife, surnamed Oanh, said. "I don't know what they do at night, but they follow Truyen wherever he goes." On Nov. 5, harassment intensified when the group was joined by another group "disguised as ordinary people," though Oanh said she recognized one as a policeman because of his uniform socks. "They brought food and drinks to have a party right in front of my house," she said. When Hoang and Oanh approached the men, "they displayed a very rude attitude and even threatened my wife with a knife because she told them not to sit there," Hoang said. Calls for help to the local police brought no result, so Hoang--who holds French citizenship--and his wife appealed for assistance to the French consulate, they said. "At the beginning, we did not want to do it, and we only called the local police," said Oanh, "But they refused to come, saying they were busy in a meeting." "As there was no one who would protect us, we had to call the consulate. My husband is a French citizen, so he comes under their protection," she said. Reached by phone by RFA on Wednesday, the French consulate in Ho Chi Minh City declined to comment on the case. Nguyen Bac Truyen himself has been followed and harassed ever since his release from prison, Truyen told RFA in a recent interview. "Whenever there is a gathering of civil society groups, plainclothes policemen are assigned to watch me, threaten me, and prevent me from going out," he said. "After I was freed from prison, they followed me 24 hours a day, but for the last two months they have only watched me from 5:00 a.m. to 11:00 p.m." "However, they are very aggressive," he said. In February 2014, Truyen and his wife were dragged from a taxi and beaten by suspected police agents while traveling to meet with an Australian diplomat in Hanoi to press for the release of fellow activists detained after a police raid on his house. Hundreds of armed Vietnamese police and government agents fired gunshots and stormed the residence during the Feb. 9 raid, according to rights groups and Truyen's wife. Also on Wednesday, Vietnamese dissident Nguyen Dan Que reported increased police surveillance at his own residence in Ho Chi Minh City after learning of the harassment of Truyen and Hoang. The two new officers set to guard him are "different from the two others who were here before, but their behavior is very intimidating and aggressive," Que said. "They have not entered my house, but they walk back and forth in front of it," he said. "If I go out, they follow me."