YANGON - Mystery surrounded the whereabouts of U.N. envoy Ibrahim Gambari on Monday after he flew to Myanmar's new jungle capital to persuade the junta to end its crackdown on the biggest pro-democracy protests in 20 years.

One diplomatic source said Gambari was being made to wait until Tuesday to meet junta supremo Senior General Than Shwe, and with the streets of Yangon quiet on Monday, had gone on a trip to Lashio, in the hills of Shan state, near the Chinese border.

No reasons for the destination were offered, although one Bangkok-based diplomat said a small group of travelling European academics was in the capital, Naypyidaw, 240 miles (385 km) north of Yangon, and due in Lashio on Tuesday.

United Nations officials with Gambari were outside mobile phone coverage, the U.N. office in Yangon had not heard a word, and no other diplomats in the former capital could shed any light on his whereabouts.

The delay does not augur well for Gambari's mission, hastily arranged last week when the junta sent in soldiers to crush more than a week of monk-led mass protests against decades of military rule and deepening poverty in the former Burma.

The 74-year-old Senior General is frequently rumoured to be in poor health but -- more ominously -- has a well-deserved reputation as military hardliner who pays scant regard to the cares and concerns of the outside world.

"MINIMALIST"

The only certain thing about Gambari, a former Nigerian foreign minister, is that he was still in the country 48 hours after his arrival, a prospect that did not look likely when he arrived.

British ambassador Mark Canning said China had pushed for Gambari's mission to be as long and as far-reaching as possible, getting permission for him to fly to Naypyidaw where he met the acting Prime Minister and Information and Cultural Ministers.

He then returned to Yangon for an hour with opposition leader and democracy icon Aung San Suu Kyi, who has been under house arrest and incommunicado for nearly 12 of the last 18 years.

His immediate return to Naypyidaw sparked hopes of the seeds of "shuttle diplomacy" between a military that has been in charge for the last 45 years, and Suu Kyi's democracy camp.

"There's been an evolution in his programme. The initial pitch was minimalist. It's got a bit better, and we want to see it get better still," Canning told Reuters.

DETERMINED TO MEET JUNTA LEADER

The U.N. made clear on Sunday Gambari did not plan to leave without seeing Than Shwe, whose troops are stationed on street corners across Yangon, making it impossible even for small crowds of demonstrators to assemble.

In a sign the junta was confident it had squeezed the life out of the uprising, barbed-wire barricades were removed from the Shewdagon Pagoda, rallying point for monks leading the marches.

Soldiers and government security men, however, were searching bags and people for cameras, and the Internet, through which images of the crackdown have reached the world, remained cut.

State-run media say order was restored "with care, using the least possible force", but soldiers continued to be stationed at the four corners of Shwedagon, the country's holiest Buddhist shrine, as well as the Sule Pagoda, the other focal point of the rallies.

Having raided more than a dozen monasteries and hauled off at least 700 monks, according to the Asian Human Rights Commission, soldiers and riot police are penning the rest behind the monastery walls.

The protests began with small marches against fuel price rises in mid-August but intensified when soldiers fired over the heads of protesting monks, causing monasteries to mobilise.

The crackdown prompted criticism even from China, the closest the junta has to an ally, and condemnation from the Association of South East Asian Nations, of which Myanmar is a member.

Among 10 people the junta says were killed, the death of a Japanese video journalist, Kenji Nagai, 50, shot dead when troops opened fire on a crowd of chanting protesters, has added to the international outrage.

A Japanese envoy has arrived to ensure a full investigation into his death, although Tokyo says the small video camera he was clutching as he died near the Sule Pagoda was missing from items returned by Myanmar officials.

Footage smuggled out of the country appeared to show a soldier shooting Nagai at point-blank range.

Western governments say the death toll is probably far higher than officially acknowledged.