HANOI (AFP) — Vietnamese Catholics have rallied outside a Hanoi police station in an escalating row over disputed church land taken over by the communist state half a century ago, police and a priest said Friday.

Police detained three parishioners after at least 100 Catholics gathered outside a police station Thursday night to call for the release of several other followers who had been arrested earlier in the day, they said.

Hanoi's police chief, in a rare press conference Friday, dismissed claims by the Thai Ha Redemptorist parish that riot police had charged the peaceful crowd and beaten them using electric batons, wounding at least three.

The disturbance came amid a long-simmering dispute in which Catholics have sought to reclaim an inner-city property that came under communist state control in the years after North Vietnam's 1954 victory against the French.

Authorities this week started legal proceedings against the Dong Da district parish, where priest Father Vu Khoi Phung has led hundreds of Catholics in prayer vigils on a disputed plot of land and erected an altar.

Tensions rose Thursday after police arrested three parishioners for damaging property and disturbing public order and took them back to the local police headquarters, said Hanoi police chief General Nguyen Duc Nhanh.

"Yesterday evening around 100 parishioners, including five to six priests, from Thai Ha parish gathered before the headquarters of Dong Da district police, creating pressure, demanding the release of the accused," he said.

"At 9:30pm last night the crowd dissolved itself," General Nhanh added. "Certainly before that there was some over-reactions, like abusing the policemen in charge. And as such we had to temporarily detain three persons."

One of the priests, Father Nguyen Van Peter Khai -- who put the total number of Catholics arrested since Thursday at eight -- told AFP that police had attacked the Catholics as they sat on the street for a peaceful vigil.

"We were in the street on Thai Ha street and the police repressed the Christians using electric shocks," said Khai. "A lot of people were beaten by police, they were beaten very hard."

He showed AFP digital photographs showing two women bleeding from head wounds who he said were victims of the police baton-charge.

When asked about the claim, police chief Nhanh only said: "We never use supporting instruments to beat those who do not violate the law. These instruments are only used when police are attacked."

Nhan said police had received no complaints alleging beatings on Thursday.

He also stressed that the police investigation was ongoing, saying "all violators should be investigated and punished."

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 had improved for years, leading to Prime Minister Nguyen Tan Dung making a landmark visit to the Vatican in 2007.

However, around Christmas last year Catholics started months of mass rallies at several churches, including Hanoi's main St Joseph's Cathedral, demanding the return of church land confiscated during the 1950s land reform era.

The Hanoi People's Committee at Friday's press conference laid out their case, backed by video recordings that showed Catholics breaking a wall to the dispute site, holding mass and erecting religious icons.

Officials called the acts illegal and said Vietnam no longer entertained land claims related to seizures made in the early years of North Vietnam.

They also said Thai Ha parish had donated the land to the state in 1961.

The Catholics say the land was stolen and have vowed more prayer vigils.