CARACAS, June 24 (Xinhua) -- Venezuelan President Nicolas Maduro on Sunday warned of an anti-government plot by retired military members, and called on the armed forces to be on alert.

While presiding over a military parade marking National Bolivarian Army Day in central Carabobo state, Maduro said the plot was being organized out of Bogota, Colombia, which borders Venezuela to the south and west.

"If some day ... the Colombian oligarchy dares to attack Venezuela, we must be ready to guarantee territorial integrity," Maduro said.

Venezuela's opposition camp "has the backing of a handful of traitors there in Bogota," said Maduro, adding his country was "besieged by the northern empire (the United States) and the northern empire has the backing of Bogota's rapacious and treacherous oligarchy."

However, Venezuela has "an army that defends it, an army that loves it, an army that is ready to defend it against invaders," Maduro said.

Some 15,000 troops took part in the military parade in Carabobo, which witnessed a key battle in Venezuela's fight for independence nearly 200 years ago.