HANOI (AFP) — A row between Vietnam's communist regime and the country's Catholic community deepened Friday when authorities began building a public park on land claimed by the Church.

The prime site in the heart of the capital Hanoi was the Vatican's embassy before it was taken over by the city's communist rulers following the departure of the French in the 1950s.

Police blocked the street next to the site Friday and dozens of priests, nuns and monks looked on as work began. Bulldozers occupied the land and a fence had been knocked down, an AFP journalist saw.

The Archbishop of Hanoi said there had for some time been speculation that a park and a library would be built on the site -- a plan confirmed Thursday in the communist party daily, Nhan Dan.

Archbishop Ngo Quang Kiet told AFP Catholics would "continue to protest" against the project.

Catholic clergy and parishioners began holding mass rallies at the end of last year demanding back the property near Hanoi's St Joseph's Cathedral.

The protests ended earlier this year when the government agreed to resolve the problem, but Catholics say nothing has changed since then.

Vietnam, a unified communist country since the war ended in 1975, has Southeast Asia's largest Catholic community after the Philippines -- at least six million out of a population of 86 million.

All religion remains under state control, but Hanoi's relations with the Catholic church have improved in recent years, leading to Prime Minister Nguyen Tan Dung making a landmark visit to the Vatican in 2007.