Riot police mobilised in Honduras as outsted President Zelaya returns The interim government was caught off guard as depos

Honduran authorities have mobilised riot police, declared a curfew and shut airports after the dramatic return of Manuel Zelaya, the president ousted in a coup three months ago.

The interim government scrambled to keep control after being caught off-guard by Zelaya's appearance on Monday at the Brazilian embassy in the capital Tegucigalpa, where he drew throngs of supporters.

The deposed leader sneaked back into the central American country - apparently travelling in a car boot and a tractor, among other means - and from the sanctuary of the embassy vowed to retake power.

"I want to tell you I am committed to the Honduran people and I am not going to rest one day, one minute, until the dictatorship is toppled," he told hundreds of cheering, chanting supporters.

The interim authorities, who initially denied Zelaya was back, ordered a nation-wide lockdown and told Brazil to hand over its guest to stand trial for treason and corruption, charges levelled against him after he was forced into exile.

In a televised address the interim president, Roberto Micheletti, said Brazil would be held responsible for any violence. "A call to the government of Brazil: respect the judicial order against Mr Zelaya and turn him into Honduran authorities. The eyes of the world are on Brazil and Honduras."

Military helicopters hovered overhead and riot police lined up near the embassy.

Brazil's foreign minister, Celso Amorim, warned that any action against the president or the diplomatic compound would violate international law.

Zelaya has promised to use peaceful means but with the country deeply polarised violence could flare. Sporadic clashes since the June 28 coup between security forces and the exile leader's supporters left dozens injured and at least two dead.

Zelaya's return opened a new, volatile phase in a crisis which has divided Hondurans and confronted central America with its gravest diplomatic dispute since the cold war. The homecoming is a gamble to regain the initiative - and spotlight - on the eve of this week's UN general assembly meeting in New York.

The US secretary of state, Hillary Clinton, urged both sides to talk. "It's imperative that dialogue begin... (that) there be a channel of communication between President Zelaya and the de facto regime."

The interim rulers have been isolated internationally but until now had firm control of the impoverished coffee exporting country. Zelaya's return has galvanised his supporters. A powerful teachers union called a strike to demand his reinstatement.

In addition to the 4pm to 7am curfew "to preserve calm" the authorities have shut airports and apparently cut power to several districts in Tegucigalpa.

Since ousting Zelaya - soldiers rousted him in his pyjamas at gunpoint and hustled him onto a plane - the interim regime has ruled out power-sharing with a man it deems a radical leftist.

Venezuela's president, Hugo Chavez, celebrated his ally's return. "It was a well planned operation and it worked. Zelaya deceived the coup mongers and went in the trunk of a car and even in a tractor."

In a televised phone call to the Honduran, Chavez added: "The coup mongers should surrender power peacefully! I congratulate you for your heroic act and the Latin American people admire you!"

Zelaya, giving back to back media interviews, told Al-Jazeera television he dodged numerous obstacles during his journey. "I had to avoid military check points crossing very close to the mountains and sometimes through the valleys."

He said he was committed to peaceful means and said elements of the army could pressure the interim government to negotiate a deal.

The coup, a joint operation by the army, congress and the supreme court, sparked furious protests by Zelaya's mostly poor supporters.

Half-way through his term the rancher-turned president, elected on a centrist platform, veered left and embraced Venezuela's socialist leader. The decision was popular with many in the slums but alarmed traditional elites, the middle class and conservative institutions.

The crisis flared when he tried to hold a non-binding public consultation to ask people whether they supported moves to change the constitution. Opponents claimed it was a step towards extending Zelaya's rule and ousted him.

The Obama administration, which has no love for the Chavez ally, joined condemnation of the coup but held back from strong economic sanctions.

Crisis talks in Costa Rica, hosted by the country's President Oscar Arias, broke down without either side reaching an agreement. The strategy of the interim government was to ride out the diplomatic storm until elections in November installed a new leader.