BANGKOK -- Vietnam sentenced an 81-year-old Catholic priest and his assistant to life imprisonment and 22 followers to shorter terms for sabotage, terrorism and "propaganda against the socialist system," the Vietnam News Agency said this week.

The defendants pleaded guilty "in the face of undeniable evidence and testimonies," according to the news agency.

An additional 73 Roman Catholics were released without punishment because they confessed to lesser crimes.

The government accused the Catholic group, led by Tran Dinh Thu, 81, of establishing an underground movement called the "Army of Priests for the Virgin Mother."

VNA said Thu trained 184 "hard-core elements" that included criminals and former commandos sent by American supporters and their agents to carry out sabotage in northern Vietnam.

The group also held three- to six-day courses for Catholics that between 1978 and 1987 trained about 4,000 people, VNA said.

The official Saigon Giai Phong newspaper said Thu's group was financed by a Catholic Vietnamese group in Missouri.

Other sources said the Congregation of the Mother Co-Redemptrix in Carthage, Mo., was a sister parish to Thu's congregation in the suburbs of Ho Chi Minh City, formerly named Saigon.

Mark Bau Doan, a priest with the Missouri congregation, said the Missouri parish was poor and provided little help for the Vietnamese priests, who were only practicing their religion.

Doan said he had never heard of the "Army of Priests of the Virgin Mother" and claimed the Vietnamese government had coined the name.

The U.S. government had been contacted to help the Vietnamese priests, but officials said they were not able to intervene, Doan said.

Washington and Vietnam do not have diplomatic relations.

The Vietnamese government has said that when the Catholic group's activities at a 35-acre secret training headquarters were uncovered in May, supporters resisted security forces, fatally stabbing one police officer and injuring others.

The leaders, including Thu, escaped but were captured July 2.

"This is a counterrevolutionary organization involving quite a large number of people and operating on a rather wide area and with assistance from foreign powers," the news agency said.

"In view of the particularly serious character of the offenses, the Ho Chi Minh City People's Court sentenced Tran Dinh Thu and Chau Van Dat, his second in command, to life imprisonment and the other defendants to prison terms ranging from four to 20 years," the agency said.

It said the court, in a four-day trial, found "Thu and his 22 accomplices guilty of propaganda against the socialist system, sabotage against the policy of solidarity, disturbance of public security and terrorism."

Catholic Church officials in Ho Chi Minh City have said the activities of Thu's congregation had increased tensions between the communist government and the country's 4 million Catholics.