HANOI, Vietnam: Vietnamese police have arrested three men, including a Norwegian citizen and an Australian national of Vietnamese origin, on terrorism charges.

The arrests have drawn a different account from pro-democracy group Viet Tan, which says two of the men were abducted in neighboring Cambodia and taken by force to Vietnam.

Vietnam's Ministry of Public Security identified the three men, who were found late on September 28, as Nguyen Duc Thuan, Ho Pham Hiep Huy and Thai Cong Truong Son. It said they were arrested on September 18 while attempting to cross illegally from Cambodia into Vietnam.

According to the ministry, the men admitted to being members of Viet Tan, a US-based pro-democracy organization that Vietnam's Communist government considers a terrorist organization.

The ministry accused the three men of illegally entering Vietnam to carry out terrorist and sabotage activities. They were also accused of forging official seals and documents.

Thuan, who was born in 1974, held a Norwegian passport, while Huy, born in 1975, held an Australian passport, the ministry said. It did not give details of Son's nationality but said he was born in 1980.

Viet Tan rejected the Vietnamese authorities' account. In a statement late on September 28, the group said Thuan and Huy, who is also known as Tran Hiep, had been abducted in Cambodia and forcibly taken to Vietnam.

The group said the two men disappeared in Cambodia on the morning of September 18 while traveling to Kaoh Andaet, in the southern part of the country near the Vietnamese border.

Vietnam's Ministry of Public Security did not immediately respond to a request for comment on the allegations.

Australian Prime Minister Anthony Albanese said in Adelaide that his government was providing consular assistance to Huy and his family. The Norwegian embassy in Hanoi directed Reuters' questions to the government in Oslo.

A spokesperson for the Cambodian government said he had no information about the reported arrests.

Viet Tan strongly condemned what it described as the abduction of two of its members and disputed the charges against them.

"Viet Tan strongly condemns the abduction of two of its members in Cambodia and the fabricated charges issued by the Vietnamese communist authorities to cover up an act of transnational repression," the group said.

Viet Tan also urged the governments of Norway and Australia, along with international human rights organizations, to pressure Vietnam to release the two men immediately and without conditions.

Vietnamese authorities said their investigation was continuing. The ministry said it would prosecute the three men under Vietnamese law.