World leaders have urged Myanmar to release the Nobel peace laureate and democracy leader who was detained on Friday after violence erupted as she toured a northern town.

The government said four people were killed and 50 injured in the disturbance in a northern town during a Suu Kyi visit, but there has been a flurry of rumors in Myanmar dissidents circles -- which include many exiles in Thailand -- that she had received a head injury.

Deputy foreign minister Khin Maung Win told diplomats in Yangon that was not true.

"The minister said that reports that Aung San Suu Kyi was injured were false," said one of the diplomats who attended a briefing by Khin Maung Win.

He said the junta cited "security" as the reason they would not divulge her whereabouts.

In Malaysia, a aide of a UN special envoy to Myanmar said he still planned to visit the country this Friday, despite Suu Kyi's detention and a crackdown on her party.

"We've received no indication from the government that he can't go," said the aide to veteran Malaysian diplomat Razali Ismail.

Diplomats have voiced fears that the latest detentions could deal a death blow to stalled reconciliation talks between the generals and Suu Kyi that began in 2000.

Khin Maung Win told the diplomats it was up to Razali if he wanted to visit, but suggested he might not be allowed to meet Suu Kyi.

After the military took Suu Kyi into "protective custody" other opposition leaders were detained, her party offices were shut and colleges and universities -- traditional bastions of dissent where Suu Kyi is believed to command strong support -- were closed.