Dissidents in Vietnam say a Catholic priest who has been prominent in the country's small democracy movement has been arrested.
By Bill Hayton
BBC News, Hanoi
The spokeswoman of the Vietnam Progression Party said that police took away Father Nguyen Van Ly after questioning him in his home for a week.
The arrest seems to be part of a crackdown on the party's activities.
Father Ly has spent 14 years in prison for his opposition to Communist Party rule.
He was released in an amnesty in 2005 and is now a member of the Progression Party.
The Progression Party says he was taken from his office in the central city of Hue on Saturday afternoon by about 60 police officers.
He had been under questioning there for six days and had reportedly begun a hunger strike.
The Vietnamese authorities have not acknowledged the arrest, but earlier they confirmed his office had been raided and he was being investigated on suspicion of undermining national unity.
The party says its two founders, Nguyen Phong and Nguyen Binh Thanh, who also live in Hue, were also detained by police last week and questioned for several days.
The Vietnamese government has previously accused such dissidents of using the cover of democracy to try to undermine the country.
Vietnam's opposition movement is small and divided, but it has been making efforts to become more effective.
Earlier this week the Progression Party had announced an alliance with another illegal organisation, the "For the People Party".
However, support for both is limited to a core of democracy activists in the country's main cities.