Thailand's military-installed government said Monday it would maintain martial law because supporters of ousted Prime Minister Thaksin Shinawatra were still out to create political chaos.

The military staged a bloodless coup on Sept. 19 when Thaksin was in New York on an official trip and appointed an interim government led by Prime Minister Surayud Chulanont, a former army commander. He has promised to step down after a new constitution is drafted and a general election is held next October.

Western nations have denounced the coup as a setback for democracy and called on the Thai government to lift martial law.

"As long as the situation is still not calm, martial law cannot be lifted," Defense Minister Gen. Boonrawd Somtat said. "If there are no political undercurrents, the opportunity to lift the martial law will come faster."

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Among other restrictions on civil liberties, the law bars the public gathering of more than five people. The government has eased the restriction by allowing public gatherings but confining them to indoor areas.

Noppadol Patthama, Thaksin's legal adviser, told a news conference Sunday that Thaksin was not involved in any movement against the current government.

"Anything that cause divisiveness in Thailand, the former prime minister doesn't want it," he said.

Thaksin, a telecom tycoon-turned-politician, portrayed himself as a champion of the poor and his policies such as low-cost health care and funds for village development made him popular in rural areas.

His party won landslide victories in the 2001 and 2005 elections. However, he was increasingly opposed by the urban elite and middle class, which accused him of corruption and abuse of power.