Lawmakers allied with Venezuelan President Hugo Chavez said Thursday that authorities had foiled a plot by government opponents and the CIA to overthrow the government. The United States rejected the allegations.

An undetermined number of active and former army officers, joined by civilians, planned to attack military bases and assassinate government officials last week as part of a plot to "destabilize" the country and force the suspension of congressional elections, National Assembly President Nicolas Maduro said.

He said an attack that damaged a major oil pipeline on the eve of Sunday's elections had been part of the plan. Maduro did not provide further details.

The government has said several people were detained in the pipeline blast, but has not provided their identities.

"They wanted to suspend the elections, attack the president and kill key government leaders," Maduro said at a news conference.

Cilia Flores, a lawmaker from Chavez's Fifth Republic party, said the CIA and staff from the U.S. Embassy in Caracas were involved in the plot. She did not elaborate.

U.S. Embassy spokesman Brian Penn rejected the claims.

"Accusations of this type are unfounded," he said.

Chavez routinely accuses the United States of trying to overthrow his government, something Washington denies.

Officials at the Interior Ministry refused to comment on the alleged plot.

Opposition leaders said government allies were using unfounded accusations to turn public attention away from the low turnout that marked Sunday's elections, which gave Chavez supporters complete control of the National Assembly.

"We, as part of a democratic opposition movement, are not planning to kill Chavez or topple the government," said Henry Ramos, secretary general of the Democratic Action opposition party.

Maduro blamed the 25 percent turnout in the elections on the "terrorist campaign."

Several opposition parties boycotted the vote, saying they did not trust the electoral system. International monitors said the elections were transparent.