Argentine police has defused two bombs discovered in the ceiling of a Buenos Aires theatre, and authorities say they were timed to explode during an appearance there by Alvaro Uribe, the former Colombian president.
The bombs that were discovered on Tuesday were hidden inside the power supply for a ceiling light in the second floor of the Gran Rex theatre.
They were attached to a cellphone with an alarm set for 4:30pm local time on Wednesday, just when Uribe would have joined a post-speech cocktail with business executives and other important guests, investigative Judge Norberto Oyarbide said.
"It is a simple device but it could have caused deaths," Oyarbide said. "The damage to Argentina would have been huge."
Oyarbide spoke after personally surveying the scene where federal police bomb experts were searching for clues inside the historic theater on Corrientes Avenue in the heart of the Argentine capital.
Al Jazeera's Lucia Newman reported from Buenos Aires said that it was "a sharp-eyed employee" of the theatre who spotted the device.
"He said immediately he knew it was a bomb. It consisted of two round objects with TNT attached to a mobile phone," she said.
Uribe, who served as Colombia's president in 2002-10, had been invited to speak about his country's transformation as part of a symposium for executives organised by WOM-Latam, a private company that organises leadership seminars and sold tickets to the cocktail party for more than $500 each.
Oyarbide said that "God willing," the seminar, including Uribe's speech, would proceed as scheduled.
In an email sent earlier to the Associated Press news agency, Uribe said he was unaware of the bomb threat.
Our correspondent said no one has claimed responsibility for placing the bombs yet but "Uribe has a whole array of enemies".
“The former Colombian president has one of the world's most extensive security outfits to protect him against his adversaries," she said.
During his presidency Uribe secured a controversial peace deal with Colombian right-wing paramilitary forces that led to the demobilisation 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 (FARC), rejected negotiations with Uribe and derided him as a warmonger.
Several foreign leftists, including at least one from Argentina, have reportedly spent time with the FARC guerrillas, according to news reports.
Uribe's tough 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.