Vietnam has denied entry to two prominent rights campaigners invited to attend this week's World Economic Forum in Hanoi, as the one-party communist state continues its hard line on critics of its dismal rights record.
Leaders from Amnesty International and the International Federation for Human Rights (FIDH) were both barred from entering Vietnam for the meeting, the campaign groups said.
FIDH secretary general Debbie Stothard was held at Hanoi's airport for 15 hours after arriving on Sunday before being deported to Malaysia early the next morning.
Her "arbitrary detention" was "based on the absurd accusation that she poses a threat to Vietnam's national security", Andrea Giorgetta, FIDH Director of Asia Desk, told AFP in a statement.
Amnesty said its senior director of global operations Minar Pimple was also denied a visa to attend the WEF summit, which will host regional leaders and big names from global business.
"We condemn this decision to stifle debate... this comes at a time when freedom of expression is under deep threat in Vietnam," Amnesty's secretary-general Kumi Naidoo said in a statement Monday.
Vietnam did not respond to AFP's request for comment.
The communist country routinely jails activist, lawyers and bloggers, but a tough new administration in power since 2016 has been accused of upping the ante on its critics.
Around 40 activists have been convicted so far this year on charges ranging from acting against the state to disturbing public order, including three American citizens, according to an AFP tally.
Amnesty says that as of April this year there were 97 known activists behind bars.
Yet Vietnam is trying to boost its diplomatic profile, hosting a slew of dignitaries and summits -- including the Asia Pacific Economic Cooperation (APEC) meeting last year attended by US President Donald Trump.
But with trade on the table, critics say its allies -- including Trump's administration -- are not pressuring Vietnam's leadership enough to protect human rights and free expression.
A spokeswoman for WEF confirmed that Stothard and Pimple had both been denied entry to the meeting, but that their invitations to the forum remained in place.
The World Economic Forum on ASEAN (Association of Southeast Asian Nations) opens in Hanoi on Tuesday under the official banner of 'Entrepreneurship and the Fourth Industrial Revolution'.
Indonesian President Joko Widodo, Myanmar's de facto leader Aung San Suu Kyi -- under fire overseas for her reaction to the Rohingya crisis -- and South Korea's foreign minister Kang Kyung-wha are among the guests.