Washington  - US Secretary of State Hillary Rodham Clinton urged the government of Myanmar to immediately release democratic activist Aung San Suu Kyi, calling the latest charges against her "baseless."

Suu Kyi was taken from house arrest to a prison in Yangon to hear charges related to an unauthorized visit by a US citizen to her home. Clinton said that the charges were a pretext for keeping Suu Kyi locked up once her current term ends this month.

"I am deeply troubled by the Burmese government's decision to charge Aung San Suu Kyi for a baseless crime," Clinton said. Myanmar was formerly known as Burma.

Suu Kyi has been under house arrest for six years for leading the opposition movement against Myanmar's ruling military junta. The 1991 Nobel Peace Prize winner could face an additional three to five years in prison if convicted.

The US citizen, identified as John William Yethaw, apparently swam in a lake to reach Suu Kyi's home.

The United States has expressed concern about the health of Suu Kyi, 63, who heads the National League for Democracy (NLD) party, which won the 1990 election but has been denied power by the junta.

She was scheduled to be released May 27. (dpa)