Authorities found and deactivated a bomb Tuesday at a Buenos Aires theater where former Colombian president Alvaro Uribe was due to deliver a speech. Uribe, known for tough law-and-order policies during his 2002-2010 presidency in Colombia, had been scheduled to speak at the Grand Rex theater in downtown Buenos Aires on Wednesday, and still intends to honor the engagement. Theater security and maintenance personnel found the bomb on the second floor, where Uribe plans "to host a cocktail party with many personalities" after a press conference, said investigating Judge Norberto Oyarbide. A justice official said the cellphone-activated bomb was hidden in a lamp. Speaking to reporters at the entrance to the theater, Oyarbide said the bomb "was simple, but large enough to kill people who were very close to it." Federal police rushed explosives experts to the site and closed off traffic for more than an hour on the busy Corrientes Avenue, outside the theater, one of the largest in the Argentine capital. After an exhaustive search to check for any other devices, around 30 police officers remained at the entrance, stopping anyone from entering the building. The damage to Argentina's reputation "would have been very large" had the bomb detonated, Oyarbide said after inspecting the room. In Bogota, Colombian Defense Minister Juan Carlos Pinzon said the device apparently had not posed a massive threat, calling it "not very serious." However, he added "we reject any terrorist act, no matter how minor it may be. President Uribe has our full support; there is no reason for this." Uribe's speech to the WOM Leadership symposium 2012, a forum on management and leadership, had drawn calls from leftist groups to organize a protest. Other scheduled speakers include Manuel Estiarte with Spain's FC Barcelona football club and Guy Caron from the Cirque du Soleil circus entertainment group. Uribe, 59, will deliver his speech -- on "The Transformation of Colombia" -- as scheduled, Oyarbide said. During his presidency, Uribe secured a controversial peace deal with Colombian right-wing paramilitary forces that led to the demobilization of 30,000 fighters, and launched peace talks with the leftist National Liberation Army (ELN) guerrillas. However the country's largest leftist rebel group, the Revolutionary Armed Forces of Colombia, rejected negotiations with Uribe and derided him as a warmonger. Several foreign leftists have spent time with the FARC over the years, including Argentine national Facundo Moraresi -- code-named Camilo -- the Colombian military said last year. Uribe's hardline policies against Colombia's leftist guerrillas resulted in a wave of complaints of human rights abuses against the armed forces. While Uribe left office with high approval ratings, details about domestic spying on journalists, judges and opposition politicians, as well as corruption among supporters, have emerged in recent years. A string of former top officials from his administration have been put on trial, including Bernardo Moreno, his former chief of staff, and ex-agriculture minister Andres Felipe Arias, a friend of the ex-president.