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HANOI — Vietnam listed a U.S.-based group still loyal to the now defunct state of South Vietnam as a terrorist organization on Tuesday, the Ministry of Public Security (MPS) said.

The California-based Provisional Government of Vietnam, led by U.S. citizen Dao Minh Quan, established groups inside Vietnam to "execute acts of terrorism and sabotage, and assassinate officials", the ministry said in a statement.

A Vietnamese naval soldier stands guard in the South China Sea in this 2013 file photo. Reuters

Quan was a "former lieutenant" of the U.S.-backed Republic of Vietnam, the statement said, referring to the now defunct state, also known as South Vietnam, which once ruled the southern half of the country until the Vietnam War ended in 1975.

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Quan did not immediately respond to a request for comment. A U.S. Embassy spokesman in Hanoi said the organization is not designated as a terrorist group by the U.S. State Department.

Despite sweeping economic reform in Vietnam, and increasing openness toward social change, including gay, lesbian and transgender rights, the ruling Communist Party retains tight media censorship and does not tolerate criticism.

Earlier this month, Vietnam jailed four men for flying the flag of South Vietnam. The flag, a bright yellow rectangle with three thin horizontal stripes, is used by political activists in Vietnam who oppose the Communist-controlled government in Hanoi.

A video on a website the MPS said was operated by Quan's group showed a convoy of cars moving through a U.S. town, some of which were flying the flag of South Vietnam. The website describes Quan as the "Prime Minister" of the Provisional Government of Vietnam.

In late December, a Vietnamese court jailed 15 people for their part in an alleged April bomb plot by Quan's group at Tan Son Nhat airport, the transport hub which serves Ho Chi Minh City — formerly known as Saigon, the capital of South Vietnam.

Fifteen people acted on instructions from an overseas group which had used social media to spread propaganda and recruit its members, local media said, citing the court indictment.

Vietnam, one of the top 10 countries for Facebook users by numbers, has called for tougher internet controls and set up a military cyber unit to fight "wrong" views online.

The group "planted fuel bombs in the car park and at the arrival hall at Tan Son Nhat International Airport" in April, 2017," Tuesday's MPS statement said.

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