UN envoy Ibrahim Gambari is demanding Burma's military government stop arresting pro-democracy activists, and release all political detainees.
He told journalists in Bangkok Monday that Burma's latest arrest of leading dissidents is extremely disturbing. Rights groups have said four of Burma's most prominent political activists were arrested in the past few days.
They are among thousands of monks and activists detained since Burmese authorities stopped mass demonstrations with deadly military force last month.
Gambari is in Thailand for talks with top officials as part of an Asian tour to gather international support for political reconciliation in Burma.
He heads next to Malaysia, before going to Indonesia, India, China and Japan. He then plans to return to Burma, where he held talks last month with military leader Senior General Than Shwe and detained democracy leader Aung San Suu Kyi.
Information for this story is provided by AP, AFP, and Reuters.