Hanoi - Police in Vietnam launched a criminal investigation into protests over land claimed by a Catholic church parish in Hanoi, claiming protesters illegally broke into the disputed plot, officials said Thursday. Hundreds of parishioners of the Thai Ha Diocese in Hanoi broke down a 6-metre section of a wall surrounding the 16,000-square-metre plot on August 15, erected two icons of the Virgin Mary and a crucifix, and began praying.

Both the church and the Hanoi government claim ownership of the land. A church official said the church has papers proving the land belongs to it, while the People's Committee of Hanoi said the church granted the land to the city in the early 1960s.

"We bought the land in 1943 with the intention of building a new church, but due to the war, we couldn't build the church," said Father Vu Khoi Phung, head of Nam Dong Church, which abuts the disputed land.

Phung said the city government took the land in 1961 and transferred it to a textile company.

"We have been trying for many years to get back the land, but the city government kept saying there is not enough of a basis to settle the dispute," Phung said. "This has made parishioners upset, forcing them to break into the plot earlier this month."

The district's police Wednesday launched an investigation into the case on charges of "destroying or deliberately damaging property" and "causing public disorder," deputy department head Nguyen Van Thanh said.

"We have not arrested anyone yet, but we will if necessary," Thanh said.

The city's People's Committee issued a decision on Wednesday to revoke ownership of the land from the textile company, the Hanoi Moi newspaper said.

The newspaper said the city decided to launch the investigation and revoke the land because city authorities had "mobilized every measure to patiently educate and persuade, but the church still refuses to stop its illegal activities."

Father Phung said the church would pursue the case to its end, though his parishioners have been strongly criticized by the city's state-run media, including newspapers and televisions stations.

"It's unfair," Thanh said. "The city has a wide range of media while the parishioners do not have any forum to raise their voice."

According to the Vietnamese penal code, destroying or deliberately damaging property carries a maximum sentence of life in prison, while causing public disorder carries a sentence of up to seven years.