Undercover BBC correspondent: 'If I was to openly talk to anybody about politics, I and they would be arrested within a couple of minutes'
South East Asian leaders have expressed "grave concern" in their first official response to the trial of Burma's opposition leader Aung San Suu Kyi.
A statement by Asean - a 10-nation grouping that includes Burma - called for proper medical care for Ms Suu Kyi.
It warned the "honour and credibility" of Burma's government were at stake.
The 63-year-old, whose health is frail, is facing a second day on trial at Rangoon's Insein prison, charged with breaking the terms of her house arrest.
As a member of Asean, Burma "has the responsibility to protect and promote human rights", said the statement issued by Thailand, which currently chairs the bloc.
"With the eyes of the international community on Myanmar (Burma) at present, the honour and the credibility of the government are at stake," it added.
The BBC's Jonathan Head in Bangkok says the statement is unusually strong for Asean, which has a tradition of not criticising the internal affairs of its members.
But he says that as Asean has discovered to its great embarrassment since admitting Burma as a member 12 years ago, its voice carries little weight with the military rulers.
The closed-door trial of Aung San Suu Kyi, whose health is known to be fragile, began on Monday amid tight security.
A BBC reporter in Rangoon - whose name is being withheld for his safety, because all foreign journalists are barred from Burma - says dozens of supporters gathered near the jail in quiet protest.
A LIFE IN DETENTION
1988: Military junta comes to power after crushing pro-democracy uprising
1989: Martial law declared; opposition NLD leader Aung San Suu Kyi put under house arrest
1990: NLD wins elections; result rejected by the ruling junta
1995: Suu Kyi released from house arrest, but movements restricted
Sept 2000: Put under house arrest again when she tried to defy travel restrictions
May 2002: Released unconditionally
May 2003: Detained after clash between NLD and government forces
Sept 2003: Allowed home after operation, but under effective house arrest. In the years since, the orders for her detention periodically renewed
But riot police set up barbed wire barricades to prevent them getting too close, and plain-clothes officers filmed them.
Ms Suu Kyi is on trial, along with her two female assistants, for violating the terms of her house arrest after a US man, John Yettaw, swam to her lakeside home earlier this month.
Mr Yettaw is also facing charges.
According to Burma's constitution, Ms Suu Kyi's latest period of detention was to expire on 27 May, and many observers see the case as a pretext to ensure she is in jail during next year's elections.
She has already spent 13 of the past 19 years in jail or detained in her home, and faces a further three to five years' imprisonment if found guilty of these latest charges.
It is unclear how long the trial will take, but estimates range from a few days to several weeks, as the government is expected to summon 22 witnesses to support its claim.
The outrage expressed by Western governments will make little difference to Burma's generals if past experience is any guide.
Perhaps China - Burma's biggest trading partner - is the only country that can influence it, analysts say.
The EU plans to ask Premier Wen Jiabao to speak out on behalf of the detained opposition leader - but such a break with China's customary silence seems unlikely, analysts say.