Singapore expressed concern over the military coup in Thailand and called for a quick return to political normalcy in its Southeast Asian neighbor.

"Singapore joins the rest of the international community in watching the latest developments in Thailand with concern. We hope all parties involved will work towards a positive outcome," a spokesman for the Ministry of Foreign Affairs said in a statement.

"Thailand is an important country in the region and prolonged uncertainties there will be a setback for Thailand and the region as a whole. We hope that the situation will return to normal as soon as possible".

Singapore's powerful state-linked investment company Temasek Holdings is at the centre of the political crisis that culminated in Tuesday's bloodless coup against Prime Minister Thaksin Shinawatra.

Australia and New Zealand issued sharp condemnations after the overthrow of Prime Minister Thaksin Shinawatra by forces loyal to General Sonthi Boonyaratglin, slamming the military move as undemocratic.

"It's unacceptable for the military just to overthrow a government in this way," Australian Foreign Minister Alexander Downer told local media from New York, where he was attending the UN General Assembly.

"We want to see a return to democratic rule," Downer said in an interview with the Australian Broadcasting Corporation.

In New Zealand, Prime Minister Helen Clark expressed shock at the news from Bangkok, and dismay that efforts to stage new elections in Thailand after the nullification of April snap polls had been derailed.

"New Zealand condemns any process which seeks to overturn a government by unconstitutional and undemocratic means," Clark said.

"New Zealand urges all political and military players to resolve their differences peacefully, and to act in accordance with Thailand's democratic principles."

Japanese Foreign Minister Taro Aso said it was "regrettable" that the armed forces had seized power, adding that officials in Tokyo hoped "democratic order" would soon be restored.

In Malaysia, which shares a border with Thailand, Prime Minister Abdullah Ahmad Badawi said he was "really shocked" by the coup and echoed Japan's calls for a return to democratic rule.

A spokesman for Singapore's foreign ministry said: "Thailand is an important country in the region and prolonged uncertainties there will be a setback for Thailand and the region as a whole.

"We hope that the situation will return to normal as soon as possible".

Also in Singapore, where the International Monetary Fund and the World Bank were wrapping up their annual meetings, IMF spokesman Bill Murray said it was "too early for us to assess the impact on financial markets".

Elsewhere in the region, reactions remained muted, with some governments expressing concern about the need for a return to the rule of law in Thailand but stopping short of directly criticising Sonthi.

"We hope Thailand will restore peace according to legal procedures," a spokesman for the South Korean foreign ministry said in Seoul.

Officials in the Philippines and Laos deemed the coup an "internal" matter, saying they would monitor developments and issue statements later on.

Manila Wednesday urged its citizens in Thailand to stay at home after a military takeover that toppled the government of Prime Minister Thaksin Shinawatra. The Foreign Affairs Department advised its 7,000 citizens there to "stay at home and avoid crowds". "Our advice to Filipinos in Bangkok is to remain in their houses if they don't need to go out," Ambassador Antonio Rodriguez told a Manila television station.

Canberra urged its citizens to reconsider any non-essential trips to Thailand, saying they should "exercise extreme caution", and urged those already in the country to remain on alert for possible violence.

New Zealand, Japan and China also urged their nationals to delay any trips if possible, and told those already in the country to remain indoors until the situation became more clear.

In Laos, foreign ministry spokesman Yong Chantalangsy said no border points had been closed, including the Friendship Bridge linking Laos and Thailand over the Mekong River, about 20 kilometres (12 miles) south of Vientiane.

Agencies