Bangkok, Thailand -- Thailand's military coup leaders began on Friday probing alleged corruption under ousted billionaire leader Thaksin Shinawatra and sacked police officials tied to the former prime minister.

Thailand's Army Commander-in-Chief Gen. Sondhi Boonyaratkalin listens to a reporter's questions in Bangkok Wednesday, Sept. 20, 2006.  [AP]

Additionally, the coup leaders banned political activity and detained four top members from Thaksin's administration.

Speaking in London on Thursday, Thaksin urged the military to quickly arrange fresh elections.

Thai army chief Gen. Sonthi Boonyaratglin, the country's self-proclaimed interim leader, earlier had promised to restore democracy as soon as possible.

A spokesman for the military leaders who staged the takeover said Thursday that four ministers from Thaksin's administration had been detained.

Two of the four were being held at an army guest house north of Bangkok and two were at army headquarters in the capital, said the spokesman, who didn't want his name used. He said the men will be held until a new prime minister is appointed.

Among the detainees is former Deputy Prime Minister Chitchai Wannasathit. The others are Newin Chidchob, the minister attached to the prime minister's office; Yongyut Tiyapairat, the minister of Natural Resources and Environment; and Cabinet Secretary General Prommin Lertsuridej.

The announcement of the arrests came on the same day as the junta said it was banning all political meetings and the registration of new political parties.

The junta said the action was taken to maintain peace and order. It did not give a timeframe.

"To ensure the constitutional monarchy is functioning after reforms have been completed, the Political Reform Council has ordered political parties to halt all meetings and political activities," it said in a statement read out on television, Reuters said.

The Nation newspaper reported Friday that the military will set up a committee to investigate the assets of Thaksin and 15 members of his cabinet.

It said two judges and a former central bank chief were likely to be on the six-person panel to probe Thaksin, his wife and other relatives as well as political colleagues, Reuters reported.

Thailand's greatly revered king reportedly endorsed the military coup in a statement from the palace.

The statement came after King Bhumibol Adulyadej met Sonthi, who staged the coup Tuesday while Thaksin was in New York to attend the U.N. General Assembly.

In a nationally televised address Wednesday, Sonthi declared the coup d'etat complete and promised power would be returned to the people as soon as possible.

Sonthi met throughout the day with government officials, members of parliament and leaders of other institutions, such as universities, seeking their endorsements.

He said his new ruling council "has so far received cooperation from all sectors of Thai society without any resistance."

Speaking from London, England, Thaksin said Thursday he would take a "deserved rest," and urged the military leaders of his country to quickly arrange for elections. 

In a statement handed by an aide to reporters, Thaksin urged "all parties to find ways and means to reconcile and work toward national reconciliation for the sake of our king and country."

Meanwhile, an exiled Muslim rebel leader on Thursday welcomed the Thaksin overthrow, saying the coup could help resolve a bloody Islamic insurgency in the country's south, The Associated Press reported.

"It is the right thing that the military has taken power to replace the Thaksin Shinawatra government," said Lukman B. Lima, an exiled leader in one of several groups fighting the central government for a separate Muslim state.

"We hope that the political (situation) can be resolved under Gen. Sonthi Boonyaratglin as the new leader," Lukman said.

Sonthi, 59, known to be close to Thailand's constitutional monarch, is a Muslim in a Buddhist-dominated nation.

He was selected last year to head the army, partly because it was felt he could better deal with the Muslim insurgency in the south, where 1,700 people have been killed since 2004.

He has urged negotiations with the separatists, in contrast to Thaksin's hard-line approach.

On Wednesday, a spokesman for UN Secretary-General Kofi Annan said Annan wanted civilian rule and new elections "as quickly as possible."

The United States, a longtime ally, declared itself "disappointed" in the coup and urged the restoration of civilian rule as soon as possible.

Meanwhile, political uncertainty flowing from Tuesday's military coup has prompted investment bank Morgan Stanley to cut its Thai GDP growth forecast sharply. 

Thailand now has had 18 coups since World War II. Rumors of the latest had been swirling around Bangkok in recent weeks as Thaksin battled considerable pressure to step down.

The telecommunications billionaire has been accused of abusing the country's system of checks and balances and bending government policy to benefit his family's business.

He had called elections in April, three years early. But the country's constitutional court ruled that vote was unconstitutional, and a new round of balloting had been scheduled for November.