AFP - A UN envoy travelled to Myanmar's western border Tuesday as part of a human rights inspection ahead of polls, as campaigners denounced the junta's treatment of ethnic groups in the area.

The trip to the region on the border with Bangladesh is part of a five-day mission to assess the military regime's progress on rights ahead of elections promised this year, the first in Myanmar for two decades.

Tomas Ojea Quintana left Yangon for Sittwe in Rakhine state on the state-run airline after a two-hour delay because of high winds at his destination, a Myanmar official said on condition of anonymity.

"Mr Quintana departed for Sittwe at 9:20am with Myanmar Airways," the official said on condition of anonymity.

Details of who he would meet in the area were not released but Rakhine is home to thousands of Rohingya, an impoverished Muslim minority group that Myanmar refuses to recognise, and to local activists.

Amnesty International released a report Tuesday detailing the repression of activists including Rakhine monks, who the group said led a 2008 uprising that was bloodily suppressed with the loss of at least 31 lives.

"Any resolution of the country's deeply troubling human rights record has to take into account the rights and aspirations of the country's large population of ethnic minorities," the London-based group's Myanmar expert Benjamin Zawacki said.

Many Rohingya have fled to Bangladesh where they are now facing mass arrests and no access to proper food and shelter, according to activists at The Arakan Project in a statement released Tuesday.

Quintana began his five-day trip on Monday, days after Myanmar authorities freed a key aide to democracy icon Aung San Suu Kyi but amid criticism of the government's election plans.

Quintana met judges and opposition lawyers in the former capital Yangon on Monday but officials said there were no plans yet for him to meet either Suu Kyi or reclusive junta head Than Shwe.

Suu Kyi's party deputy, Tin Oo, 83, was freed from seven years in detention at the weekend, but he immediately called for the release of more than 2,100 other political prisoners.

Nobel Peace laureate Suu Kyi remains under house arrest and has said it is too early for her National League for Democracy (NLD) to decide if it will take part in polls that critics deride as a sham.

Suu Kyi's house arrest was extended last August by 18 months when she was convicted over an incident in which a US man swam to her house, effectively ruling her out of the polls and sparking global outrage.

Quintana, making his third trip to Myanmar since his appointment in 2008, is due to return to Yangon on Thursday to visit the notorious Insein prison, where many dissidents are held, and will later meet ethnic representatives.

He will go to the remote capital Naypyidaw on Friday to meet senior government officials before leaving Myanmar, which was formerly known as Burma.

Quintana has said he wants to meet Suu Kyi, who has been detained for 14 of the last 20 years since the NLD won the elections in 1990 but was prevented from taking power by the military.

In a statement last week Quintana said 2010 was "a critical time for the people of Myanmar".