At least three well-known activists were arrested as police broke up a rowdy protest outside the Hai Phong People's Court in support of Doan Van Vuon, who rose to prominence by leading his family's resistance against authorities.
Court documents said seven policemen were injured in the January 2012 incident as the Vuon family armed themselves with homemade shotguns to hold off local officials trying to evict them from their fish farm in Tien Lang district, 90 kilometres (55 miles) east of Hanoi.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Their rare act of defiance in the tightly-controlled communist state triggered a nationwide outpouring of support, with even Prime Minister Nguyen Tan Dung saying the eviction was "illegal" and promising to prosecute corrupt local officials.
Vuon -- who served in the army in the 1980s -- is being tried for attempted murder with three other male relatives, all of whom have all been in detention since the incident.
The charge carries a maximum sentence of death.
His wife and sister-in-law are being tried on a charge of resisting officers, in a hearing expected to last until Friday.
According to the indictment read out in court on Tuesday, Vuon and his relatives used the homemade weapons and demonstrated "murderous behaviour" towards public officials.
"I knew the use of weapons was not in accordance with the law... my view was that the eviction was illegal so if they did not stop I would be forced to fight it," Vuon, who was flanked by two policemen, calmly told the court.
"We just wanted to threaten them" and did not intend anyone to get hurt during the standoff, he said, adding that the family had decided to fight back to try to draw the attention of the country's leaders to their plight.
Five former local officials in the area will go on trial next Monday over the destruction of Vuon's house.
Vuon's supporters -- who travelled to Hai Phong in droves to show support for the 50-year-old -- voiced fears he would receive a harsh sentence as a deterrent to others.
"If the government gives a lenient sentence it may urge other people to react more strongly," pro-democracy campaigner Pham Hong Son, who has spent years in jail, told AFP before police forced reporters to leave the area.
Police on the outskirts of Hai Phong prevented busloads of pro-democracy activists and Catholic supporters -- the Vuon family is Catholic -- from entering the northern port city, AFP reporters saw.
Land is a divisive issue in communist Vietnam. It is wholly owned by the state and rights of use are not always clear or protected.
Millions of rural tenants like Vuon are vulnerable to the whims of local officials, who can reclaim land for vaguely-defined "public interest" reasons, which experts say leads to widespread local corruption.
More than 70 percent of all complaints lodged with authorities nationwide concern land. Twenty-year land-leases issued in 1993 will expire this year and the government has not made it clear how the issue will be resolved.
