(BBC) UN envoy Ibrahim Gambari has met Burma's military leaders and detained opposition leader Aung San Suu Kyi , diplomatic sources say.
Mr Gambari is attempting to mediate between the junta and the opposition, and end a bloody crackdown on mass pro-democracy protests.
The sources said Mr Gambari almost certainly met senior general Than Shwe .
Ms Suu Kyi's National League for Democracy easily won elections in 1990, that were annulled by the generals.
Mr Gambari is said to have met the generals in the capital Naypyidaw and Ms Suu Kyi in the main city of Rangoon.
Burma has seen almost two weeks of sustained popular unrest.
But the number of protesters on the streets is now much smaller than at the height of the rallies, as the military has heavily garrisoned Rangoon and Mandalay to deter dissent.
Buddhist monks, who were initially in the vanguard of the protests, have been arrested or confined to their monasteries.
The government says 10 people were killed last week in the suppression of the opposition protests.
Diplomats and activists say the number killed was many times higher.
The country's leadership usually ignores outside pressure.
But the crackdown has prompted rare criticism from China and the Association of South East Asian Nations ( Asean ), of which Burma is a member.
After talks by telephone with his UK counterpart Gordon Brown, Chinese Prime Minister Wen Jiabao said Beijing hoped peace would return to Burma quickly.
In a statement, Mr Wen said China wanted a peaceful resolution to the situation in Burma.
" China hopes all parties concerned in [ Burma] show restraint, resume stability through peaceful means as soon as possible, promote domestic reconciliation and achieve democracy and development."
EU foreign policy chief Javier Solana urged China to lean harder on Burma.
A Japanese envoy is also due to arrive in the country, to ensure a full investigation into the death of Japanese video journalist Kenji Nagai.
Video of his death last Wednesday appears to show a soldier shooting him at close range as security forces cleared central Yangon of protesters.