By Nga Pham
BBC Vietnamese service
A mass protest over the Vietnamese government's land policies is gathering force, ahead of the opening session of the newly-elected National Assembly.
The protesters are demanding the return of their land
Witnesses say hundreds of peasants from the Mekong River Delta are surrounding the offices of the National Assembly in Ho Chi Minh City.
A smaller protest is also reportedly being held in the capital, Hanoi.
The protesters are demanding the return of their land, and for any wrongdoing by local officials to be punished.
Both protests have been going on relatively peacefully for several weeks, and received little coverage in the local media.
However, as the protest in Ho Chi Minh - Vietnam's second city and the main economic hub - has hotted up in the last few days, residents have started complaining about traffic disruption.
Land protests are not unseen in Vietnam, but correspondents say a demonstration of this scale and intensity is rare.
Security forces have begun to get involved to make sure the protest does not get out of control.
Local officials in the Mekong Delta provinces have been urged to come to Ho Chi Minh City to "persuade their people to go home", with promises that their complaints will be dealt with appropriately.
Meanwhile, a deputy minister of security was quoted by state media as saying that there had been a certain involvement of "reactionary forces overseas".
Last Sunday, Deputy Prime Minister Truong Vinh Trong called an urgent meeting with provincial leaders.
He asked for a prompt investigation into the case and warned that the Communist Party would not tolerate inappropriate measures.
Land seizures in the name of economic development have been a much-debated topic in Vietnam, where the state maintains the sole ownership of land.
Peasants frequently complain about unfair compensation and criticise the laws on land use, which in their opinion have too many loopholes and are easily abused by corrupt local government officials.
The new 500-strong Vietnam National Assembly, elected last May, is to begin its first session on Thursday in Hanoi.
With the mass protest intensifying outside, the deputies will no doubt have many things to debate.