CARACAS, Dec. 2 -- A massive power outage struck multiple states in Venezuela Monday night, and President Nicolas Maduro suggested it might be an act of sabotage by the opposition.

The blackout took place shortly after 8 p.m. local time (0000 GMT) in 10 states, including the capital, and lasted for almost one hour, resulting in interruptions to subway and airport operations.

Maduro described the cause as unusual, saying it was most likely an opposition conspiracy to stoke up public discontent against the government before the Dec. 8 national municipal elections.

"I ask the people to stay alert," he wrote on his Twitter account.

National Assembly President Diosdado Cabello also blamed the opposition. "I have no doubt that today's electricity sabotage is part of the right-wing's plan," he said on Twitter.

Electricity Minister Jesse Chacon said: "We ask Venezuelans for patience. It's noteworthy that the problem is in the same place as the sabotage in September."

Opposition leader Henrique Capriles rejected the government's accusation as extremely irresponsible.

A similar power outage on Sept. 5, which Maduro also attributed to opposition sabotage, affected more than 70 percent of the nation.