Opposition leader Aung San Suu Kyi faced a second day of hearings Tuesday as international criticism of her trial grew.
Hundreds of police, some in full riot gear, were deployed along roads leading to Insein prison where the trial is being held behind closed doors.
Twenty-two witnesses are expected to testify against Aung San Suu Kyi in the trial, which her lawyer says could last three months.
On Monday, the court heard from Lieutenant Colonel Zaw Min Aung, the police officer who signed the original complaint against the Nobel Peace laureate.
Outside of Burma, calls for Aung San Suu Kyi's release and an end to the trial continued. In Manila, protesters rallied in front of the Burmese Embassy, while around 400 Burmese activists and others gathered in the Burma - Thai border town of Mae Sot to show their support.
Even Burma's partners in the Association for Southeast Asian Nations - who rarely criticize one another - have expressed their "grave concern" over the trial, and warned that Burma's credibility was at stake.
Rights groups and Western governments say the trial is an excuse to extend Aung San Suu Kyi's house arrest, which is due to expire at the end of this month.
Aung San Suu Kyi and two female assistants were charged after an American intruder swam across a lake earlier this month and sneaked into her residence. If convicted, she faces up to five years in prison.
The American man, John Yettaw, whose unauthorized visit triggered the proceedings, is also on trial for breaking Burma's security and immigration laws.
Aung San Suu Kyi has been scheduled to be freed May 27, after six consecutive years of house arrest. She has been under house arrest for more than 13 of the past 19 years.
Her trial also comes ahead of Burma's controversial 2010 elections, which have been criticized as a sham aimed at reinforcing the Burmese military's grip on power.
Aung San Suu Kyi's National League for Democracy won elections in 1990, but the country's military junta refused to recognize the results.
Some information for this report was provided by AP.