Build-up of troops on Colombia's borders sparks fears of war

Ecuador's President, Raphael Correa, said there could be "no justification" for the killing of Raul Reyes, thought to be the number two in Colombia's Farc rebellion, along with 16 other guerrillas in a bombing raid on Saturday.

In a further sign of hostilities, President Chavez's government said last night that it was expelling Colombia's ambassador and other diplomats from Venezuela.

Colombia accuses the Farc of using bases in Ecuador and Venezuela to launch attacks inside the country. Mr Uribe, whose father was kidnapped and killed by the guerrillas, has refused direct negotiations with the rebels and pursued a military solution, assisted by the largest US military aid budget outside the Middle East.

Fidel Castro, who retired as President of Cuba last month, voiced his support for Venezuela and Ecuador in an essay published in the Communist Party daily Granma. "We can plainly hear the trumpets of war to the south of our continent as a consequence of genocidal plans of the Yankee empire," Mr Castro wrote.

Regional analysts were surprised by Colombia's border incursion and said that while the escalation was largely posturing for domestic audiences, a conflict was possible. "This is an alarming degeneration in the region and has ominous overtones that could lead to provocative developments," said Larry Birns, director of the Council on Hemispheric Affairs, a Washington think-tank.