Bangkok, Thailand ? In the dead of night and without firing a shot, Thailand’s military overthrew popularly elected Prime Minister Thaksin Shinawatra on Tuesday amid mounting criticism that he had undermined democracy.

The sudden, well-orchestrated coup – the first in 15 years and a throwback to an unsettled era in Thailand – was likely to spark both enthusiasm and criticism at home and abroad. The military said it would soon return power to a democratic government but did not say when.

Striking when Thaksin was in New York at the U.N. General Assembly, army commander Gen. Sondhi Boonyaratkalin sent tanks and troops into the drizzly, nighttime streets of Bangkok. The military ringed Thaksin’s offices, seized control of television stations and declared a provisional authority loyal to the king.

The coup leaders declared martial law, revoked the constitution and ordered all troops not to leave duty stations without permission from their commanders. The stock exchange was to be closed today, along with schools, banks and government of-fices.

Bang-kok’s normally bust-ling streets emptied out early today, from shopping stalls to red light districts, as Thais and tourists learned of the coup.

Across the capital, Thais who trickled out onto barren streets welcomed the surprise turn of events as a necessary climax to months of demands for Thaksin to resign amid allegations of corruption, electoral skullduggery and a worsening Muslim insurgency. Many people were surprised, but few in Bangkok seemed disappointed.

A few dozen people raced over to the prime minister’s office to take pictures of tanks surrounding the area. “This is exciting. Someone had to do this. It’s the right thing,” said Somboon Sukheviriya, 45, a software developer snapping pictures of the armored vehicles with his cell phone.

Thaksin recently alienated a segment of the military by claiming senior officers had tried to assassinate him in a failed bombing attempt. He also attempted to remove officers loyal to Sondhi from key positions.

Sondhi, who is known to be close to Thailand’s revered constitutional monarch, will serve as acting prime minister, army spokesman Col. Akarat Chitroj said. Sondhi, well-regarded within the military, is a Muslim in this Buddhist-dominated nation.

Sondhi, 59, was selected last year to head the army partly because it was thought he could better deal with the Muslim insurgency in southern Thailand, where 1,700 people have been killed since 2004. Recently, Sondhi urged negotiations with the separatists in contrast to Thaksin’s hard-fisted approach. Many analysts have said that with Thaksin in power, peace in the south was unlikely.

In New York, Thaksin declared a state of emergency in an audio statement via a government-owned TV station in Bangkok – a vain attempt to stave off the coup. He later canceled a scheduled address to the U.N. General Assembly and made plans to return to Thailand quickly. It was not know whether he faced the possibility of being arrested if he returned.