YANGON - A court in army-ruled Myanmar has upheld a ban on two defense witnesses in the widely-condemned trial of opposition leader Aung San Suu Kyi, one of her lawyers said on Tuesday.

Although the court overturned a ban on one witness, Khin Moe Moe, the Nobel laureate's lawyer Nyan Win said he was disappointed by the ruling and would appeal the decision.

We didn't get the result we expected and we will go to a higher court to appeal, Nyan Win told reporters.

Suu Kyi, 63, faces three to five years in prison if found guilty of breaking the terms of her house arrest by allowing an American intruder to stay for two days after he swam to her home on May 4.

A conviction is widely expected in the former Burma, where the courts have often bent the law to suit the ruling generals.

Suu Kyi's next scheduled court appearance is on June 12.

But Nyan Win said final arguments in the trial, which had been delayed several times, would likely be put back again.

The final verdict on Daw Aung San Suu Kyi is now expected after two weeks, he said.

Security was tight during Tuesday's hearing, with at least 20 trucks carrying riot police assembled in front of the City Hall, the site of previous anti-junta protests in the former capital.

The military regime insists the trial will be conducted according to the law, but critics say the charges have been trumped up to keep the pro-democracy icon in detention during elections next year.

Suu Kyi has spent more than 13 of the past 19 years in some form of detention, mostly under house arrest at her home on Yangon's Inya Lake.

The banned witnesses are Win Tin, a senior member of Suu Kyi's National League for Democracy (NLD) party, and its detained vice-chairman, Tin Oo.

The court's initial decision to allow Suu Kyi only one witness, lawyer and NLD MP Kyi Win, angered activists who saw it as an attempt by the regime to sabotage her defense.

Suu Kyi is accused of committing a violation under Section 22 of a draconian security law protecting the state from subversive elements. Her lawyers argue that section is invalid because it is based on a constitution abolished years ago.

Her two female housemates and the American intruder, John Yettaw, are charged under the same law.

Suu Kyi has blamed security officials for failing to prevent Yettaw's visit, but none have been punished.

Yettaw, 53, has told the court that God sent him to warn Suu Kyi she was going to be assassinated by terrorists.

The generals have accused Western governments and critical neighbors of meddling in Myanmar's internal affairs. They have vowed to forge ahead with a seven-step roadmap to democracy expected to culminate in multi-party elections next year.

Critics say the polls will entrench nearly a half century of military rule in Myanmar.

(Writing by Martin Petty; Editing by Darren Schuettler and Sanjeev Miglani)