Three prominent critics of Vietnam's government have been arrested, a rights group said Wednesday, days after the Southeast Asian nation said it would run for another term on the United Nations Human Rights Council.

Influential rights campaigner and YouTuber Nguyen Chi Tuyen, and Nguyen Vu Binh -- a political activist who served almost five years in jail in the early 2000s -- were arrested last Thursday, Human Rights Watch (HRW) said in a statement.

Hoang Viet Khanh was arrested the following day. All three were accused of conducting propaganda against the state, HRW said.

A crackdown on dissent has been escalating in recent years in Vietnam, a one-party state.

Critics of the communist government face intimidation, harassment, restricted movement, arbitrary arrest and detention, as well as imprisonment after unfair trials, and there are reports of police torture to extract confessions, HRW says.

Forty-nine-year-old Tuyen, who is also known as Anh Chi, helped found the prominent independent civil society group No-U, which protests China's territorial claims in the South China era.

One of his YouTube channels, Anh Chi Rau Den, has produced 1,600 videos and is followed by 98,000 subscribers.

Binh, 55, worked as a journalist at the official Communist Party of Vietnam's journal for almost 10 years before he resigned and attempted to form an independent political party. He was sentenced to seven years in jail for espionage in 2003.

The arrest of Khanh, a citizen journalist, was reported in Vietnamese state media. Authorities have not confirmed the arrests of any of the three.

The arrests came just days after Vietnam's foreign minister Bui Thanh Son called on countries to support its bid for re-election as a member of the United Nations Human Rights Council for the 2026-2028 tenure.

  Political groups condemned 

 Separately on Wednesday, Vietnam declared two political groups operating from the United States as "terrorist organisations", accusing them of involvement in gun attacks that killed nine in the country's Central Highlands last year.

Though Vietnam heavily cracks down on critics, few anti-government organisations or activists have been jailed for terrorism, which is punishable by death in the authoritarian state.

The two organisations named by Vietnam's public security ministry were the Montagnard Support Group Inc (MSGI) and Montagnard Stand for Justice (MSFJ).

The ministry accused the MSGI of recruiting members in Vietnam, inciting protests and armed riots, giving money and weapons and directing terrorist attacks to try to create a separate "Dega state" in the Central Highlands.

The Dega are one of the ethnic minority groups from Vietnam's Central Highlands, an area that has long been a hotbed of discontent over issues that include land rights.

The ministry also accused the MSFJ of conducting terrorist attacks to establish a "private state" in the Central Highlands.

Vietnam jailed nearly 100 people on terrorism charges over the shooting attacks last year on police headquarters.

There are currently 175 activists in jail in the country, according to The 88 Project, a Vietnam-focused human rights organisation.

Last week the group said Vietnam's leaders had issued a secret directive that would frame almost all international commerce and cooperation as a threat to national security, adding that it would further entrench "systematic" human rights violations.

Directive 24, as it is called, was issued in July 2023 just two months before US President Joe Biden visited Hanoi as Washington seeks a reliable alternative trading partner to China.