TEGUCIGALPA - Ousted Honduran President Manuel Zelaya vowed to return to Honduras as angry supporters clashed with riot police near the presidential palace here.
Zelaya told a meeting of regional leaders in the Nicaraguan capital Managua he planned to travel on Tuesday to Washington, where US President Barack Obama has denounced the coup as illegal.
From there he would go to New York and address the UN General Assembly, which held emergency talks on the crisis on Monday.
And he added: "I go to Tegucigalpa on Thursday," thus setting up a potentially explosive showdown with the newly installed administration of congressional leader Roberto Micheletti.
Zelaya also accepted the offer of Jose Miguel Insulza, the head of the Organization of American States, to accompany him back to Honduras, along with leaders of other friendly countries who may wish to travel with him.
Venezuelan President Hugo Chavez urged Zelaya to meet with Obama, saying the US president's attention to the matter could "deliver a major blow" to those who ousted Zelaya.
In Washington Monday, Obama told reporters: "We believe that the coup was not legal and that President Zelaya remains the president of Honduras, the democratically elected president there."
He called for international cooperation to solve the crisis peacefully.
The State Department warned US citizens against travel to Honduras and advised those already there to stay indoors.
In Tegucigalpa itself, hundreds of angry Zelaya supporters defied a government curfew and erected barricades near the presidential palace.
They threw rocks and Molotov cocktails and used pipes and metal bars against shield-bearing riot police. The security forces cracked down with tear gas and gunfire, an AFP photographer said.
The violence, the most serious unrest in years in this Central American country, left several demonstrators and security forces injured.
Zelaya was deposed on Sunday when troops bundled the 57-year-old out of his bed in pyjamas and whisked him away to exile in Costa Rica.
Just hours later, the Honduran Congress swore in its speaker Micheletti as the interim president until January.
It was he who imposed the 48-hour curfew on the capital.
Politicians, business leaders, most communications media and a good part of the population have applauded Zelaya's overthrow, despite the violent street protests.
Micheletti brushed off international condemnation of the takeover, insisting he "had come to the presidency not by a coup d'etat but by a completely legal process as set out in our laws."
But Zelaya insists he remains the elected leader, and scores of young people, many wearing scarves to cover their faces, protested in the capital Tegucigalpa Monday. Shots were heard in the city late Sunday.
"President Mel is the only one," said Joseph, who was wielding an iron bar, and using the president's nickname.
"It was a coup, Mel Zelaya did not resign," agreed Amilcar Umanzo, brandishing a human rights manual in his hand. "The political and economic class united to overthrow the constitutional president."
The military moved against Zelaya after he pressed ahead with plans for a referendum on changing the constitution to allow him to run for a second term in November elections.
But it was almost uniformly condemned in Latin America, the United States and Europe.
Meeting in Managua, the Rio Group, an organization of 22 Latin American countries, condemned the coup and called for Zelaya's "immediate and unconditional" reinstatement.
They also said they were recalling their ambassadors, as did Mexico and Chile.
Honduras' neighbors in Central America agreed to isolate Tegucigalpa politically and economically, ordering the regional bank to suspend loans and payments to Honduras.
Russia and Canada have joined the growing list of nations speaking out against the overthrow, and the European Commission called an urgent meeting with Central American ambassadors to consider the future of trade talks.