The party of Myanmar's detained pro-democracy leader Aung San Suu Kyi urged the country's junta Monday to end the "torture" of monks and activists rounded up after last month's protests.

The European Union, meanwhile, agreed to strengthen sanctions against the military regime if it failed to engage in dialogue with the country's pro-democracy forces.

The call by the National League for Democracy echoed concerns raised by a United Nations envoy who said reports of new repressive measures in Myanmar were "extremely disturbing."

The reported new arrests of dissidents, interrogations and acts of intimidation "are extremely disturbing and run counter to the spirit of mutual engagement between the United Nations and Myanmar," U.N. special envoy Ibrahim Gambari said in Bangkok, Thailand.

"These actions must stop at once," said Gambari after meeting with Thailand's foreign minister as he began a six-nation tour to seek Asia's help in pressing Myanmar to reconcile with the pro-democracy opposition.

E.U. foreign ministers meeting in Luxembourg agreed to widen the group's sanctions against Myanmar, adding a ban on imports of timber, gemstones and precious metals.

They said in a statement it was "necessary to increase direct pressure on the regime" in Myanmar, also known as Burma, by banning exports of equipment used in the country's timber and mining industries and ban imports from — and investments in — these sectors.

It said the measures — which come on top of an existing travel ban on Myanmar officials, an arms embargo and a freeze of Myanmar assets — "do not harm the general population but ... target those responsible for the violent crackdown and the overall political stalemate."

The statement by the NLD, led by Nobel laureate Suu Kyi, called for the junta to immediately and unconditionally release political detainees, and stop the "torture" of Buddhist monks, nuns, students and other people who were detained following a rare wave of massive protests last month.

Several thousand people are believed to have been arrested, and there are many reports of brutal treatment in custody.

A dissident group based in neighboring Thailand, the Assistance Association for Political Prisoners, reported last week that NLD member Ko Win Shwe, 42, died as a result of torture during interrogation after being arrested on Sept. 26. The report could not be independently confirmed.

On Saturday, security forces arrested at least four prominent political activists who went into hiding to escape a government manhunt, Amnesty International said.

They included three of the last remaining activists at large from the 88 Generation Students group, the country's boldest dissident organization. It was one of the main forces behind the protests that started on Aug. 19 over steep hikes in fuel and consumer prices and mushroomed into a unified call for a return to democracy. Myanmar has been under military rule since 1962.

Gambari, who met in Thailand with Prime Minister Surayud Chulanont and Foreign Minister Nitya Pibulsonggram, called for the release of all political detainees and asked for the International Red Cross to have access to them.

Gambari travels next to Malaysia, Indonesia, Japan, India and China before returning to Myanmar. India and China are two of the junta's biggest allies.

Earlier this month Gambari met with Myanmar junta leader Gen. Than Shwe during a four-day visit, urging the government to end its crackdown on protesters. He also met twice with Suu Kyi.

His negotiating efforts, however, have failed so far to bring about a dialogue between the two sides.

Last week, in its first-ever statement on Myanmar, the U.N. Security Council said it "strongly deplores" the government's violent crackdown on protesters and called for a "genuine dialogue" between the country's military rulers and the pro-democracy opposition.

In Luxembourg, British Foreign Secretary David Miliband told reporters that if the junta accepts Gambari's overtures to open a dialogue with its opponents, "then there will be economic incentives and economic support for the people of Burma. If the regime refuses, then obviously there will be further sanctions."

EU External Relations Commissioner Benita Ferrero-Waldner said delaying the start of the new sanctions would give Gambari's mission "the necessary leeway" to make progress.

Ferrero-Waldner said key areas of progress the EU wanted to see were the release of political prisoners, including Suu Kyi, who has been under house arrest for 12 of the last 18 years..

Myanmar's military leaders have rebuffed calls for reforms, saying the only way to bring change to the country is to follow the junta's seven-step "road map" to democracy.

The road map is supposed to culminate in a general election at an unspecified future date. But so far only the first stage — drawing up guidelines for a new constitution — has been completed, and that took more than a decade. Critics say the plan has no clear timetable and is a ruse to allow the military to cling onto power.