CUCUTA, Colombia – Venezuela moved troops toward Colombia and turned away cargo trucks at border crossings on Tuesday as tensions mounted over Colombia’s strike on a leftist rebel base in Ecuador.

Ecuador also reinforced its border with more troops and sought international condemnation of the attack, which killed a top commander of Colombia’s main rebel group and 22 other guerrillas.

Colombia said documents found at the rebel base showed the Revolutionary Armed Forces of Colombia were trying to acquire radioactive material that could be used for dirty bombs – and that Venezuela and Ecuador had deepening ties with the FARC. Venezuela and Ecuador said Colombia was lying.

The Organization of American States held an emergency meeting in Washington to try to calm one of the region’s worst political showdowns in years. Colombia apologized for the attack, but Ecuador wasn’t satisfied, calling for OAS to investigate.

Colombian President Alvaro Uribe said the International Criminal Court should try Venezuelan President Hugo Chavez for “genocide” for allegedly financing FARC, listed as a terrorist organization by the U.S. and the European Union. He cited documents in laptops Colombia says were recovered at the jungle camp that apparently refer to a $300 million Venezuelan payment.

Despite troop movements and saber rattling, Uribe said he would not allow his nation to be drawn into war.

“Colombia has never been a country to go to war with its neighbors,” Uribe said. “We are not mobilizing troops, nor advancing toward war.”

Associated Press writers Vivian Sequera in Bogota; Howard Yanes at El Amparo, Venezuela; and Fabiola Sanchez and Ian James in Caracas contributed to this report.