Yangon - UN special envoy Ibrahim Gambari arrived in Myanmar Monday for a five-day visit that aims to pressure the ruling military junta to speed up democratic reforms, address human rights and free political prisoners.

The visit is Gambari's fourth since last year to Myanmar, also known as Burma, where he has been handed a mandate by the United Nations to deal with the country's military regime in addressing international concerns about human rights violations, slow-paced political reforms and the ongoing detention of opposition leader Aung San Suu Kyi and hundreds of other political prisoners.

The State Peace and Development Council, as Myanmar's junta calls itself, has shown little willingness to comply with Gambari's overall mission.

On August 7 in Yangon, for example, Myanmar authorities arrested three members of the All Burma Federation of Student Unions and two members of the 88 Generation Students, two pro-democracy groups, whose whereabouts remain a mystery.

"Family members are not informed yet by the authorities where they are being detained, what charges they are facing, and whether they are alive or not," a statement issued by the federation said.

Myanmar has been under the equivalent of martial law since 1988 when the army unleashed a brutal crackdown on a nationwide pro-democracy movement that left an estimated 3,000 people dead and thousands more in prison.

Bowing to international pressure, the regime held a general election in 1990, which the National League for Democracy (NLD), led by Suu Kyi, won with a landslide victory.

Instead of acknowledging the outcome at the polls, the junta has blocked the NLD from power for the past 18 years, keeping Suu Kyi - who received the Nobel Peace Prize in 1991 - under house detention for 13 of those years.

One new development has been the regime's decision to allow Suu Kyi visits from her attorney, Kyi Win, this month ahead of Gambari's visit.

Gambari has been permitted to meet with Suu Kyi on past visits.

On Sunday, Suu Kyi met with Kyi Win for five hours at her Yangon-residence-cum-prison after meeting with the lawyer for the first time in five years on August 8.

Suu Kyi has been kept in near-isolation since May 30, 2003, when she was charged with disturbing the peace by campaigning in the provinces.

Under Myanmar's emergency law, political prisoners can only be kept under detention for a maximum of five years on charges of disturbing the peace, but Suu Kyi's detention was extended in May for another six months.

Myanmar's ruling junta has been sending mixed signals about the duration of Suu Kyi's incarceration. There have been hints that she might be released within six months, but many observers said they believe it is unlikely she would be released before the next general election, slated for 2010.

Suu Kyi is widely seen as Myanmar's democracy icon, and is one of the few opposition leaders with enough popular and international support to undermine the military's monopoly of political power in the South-East Asian nation. (dpa)