Vietnam's authorities have barred local activists from gathering to mark the 31stanniversary of the loss of Gac Ma (South Johnson Reef) to China ahead of a visit of President Nguyen Phu Trong to Beijing. From early morning of March 14, plainclothes agents and militia were sent to private residences of activists in Hanoi, Ho Chi Minh City and other localities to effectively place them de facto under house arrest. Some were allowed to go out but remained under close police surveillance. University lecturer Dao Thi Thu in Hanoi told Defend the Defenders that she couldn't to go to her class as undercover police and militia did not permit her to go out with her motorbike. When she tried to get a bus, police officers violently stopped her, making her watch broken. Mr. Nguyen Tuong Thuy, vice president of the Independent Journalist Association of Vietnam, said he planned to go to Hanoi's center to commemorate the 64 naval soldiers killed by the People's Liberation Army of China (PLA) in Gac Ma in 1988, he was blocked by a group of around five undercover policemen. Authorities in the capital city sent a group of dozens of women to dance near King Ly Thai To monument in the city's center where activists were used to gather in similar cases, making the place unavailable for other activities. The similar situation was in HCM City and local activists were forced to stay at home to mark the event. In previous years, authorities did not block activities from gathering but sent government's supporters to disturb the activists' commemorations. On February 27, in order to prevent activists from gathering to Tran Hung Dao Great General to mark the 40thanniversary of the invasion of the PLA in Vietnam's six northernmost provinces, authorities in HCM City removed his .... To another place. This year, for the first time in decades, some state-run newspapers covered news on the loss of Gac Ma or the Chinese invasion in 1979, however, they still avoided to name Beijing as the aggressor. Meanwhile, Nguyen Phu Trong, the communist chief, planned to go to visit China for the first time after grabbing the country's president post left by former Minister of Public Security Tran Dai Quang, who died from unclear reasons last year.