Yangon - Tin Oo, the vice chairman of Myanmar's main opposition party, has been slapped with another year of house arrest, government sources said Friday.

Authorities extended Tin Oo's detention by another year under the Law Safeguarding the State from Danger and Subversive Elements, which places a five-year maximum term on imprisonment.

Tin Oo, 82, vice chairman of the National League for Democracy (NLD) and first deputy to its leader, Aung San Suu Kyi, was put under house arrest on February 13, 2004, meaning this year would be his sixth of detention.

Nobel Peace Prize laureate Suu Kyi has been kept under house arrest since May 2003 on the same charge.

Suu Kyi's attorney has been lobbying the ruling junta to release her on the grounds that her incarceration exceeds the maximum term of five years but has had no success.

Both opposition leaders were detained for leading a political campaign in central Myanmar, also called Burma, that was ended by a violent attack on their party by pro-government thugs that left several NLD members dead and injured.

Tin Oo spent several months in a provincial jail before being put under house arrest in Yangon in February 2004.

It is widely believed that Myanmar's military regime wants to keep both Suu Kyi and Tin Oo out of the picture until after a general election scheduled for some time in 2010.

The NLD won the 1990 general election by a landslide, but they military has barred it from power.

Suu Kyi has spent 13 of the past 19 years under house arrest. She won the Nobel prize in 1992 for her struggle to bring democracy to her country, which has been under military rule since 1962. (dpa)