Venezuelan president Nicolas Maduro has accused the United States of plotting to blow up the presidential palace in an attempted coup.

On Thursday, the South American country arrested a retired air force general and 13 other people who were allegedly trying to overthrow the socialist government.

In a statement which has been dismissed by American officials as 'ridiculous', Maduro addressed national television to accuse the United States of trying to curry favor with the revolutionaries.

'It is the government of the United States that is behind the plans of destabilization and coups against Venezuela. I have come here to denounce it,' Maduro said in a televised address on Thursday.

Accusations: President Nicolas Maduro addressed the nation to say the United States tried to overthrow him

'We have dismantled a coup attempt against democracy, against the stability of our homeland.

'It was an attempt to use a group of officials from the air force to provoke a violent act, an attack.'

It has been a year since violent protests broke out in the streets of Caracas.

Venezuela's government has frequently alleged coup plots, often without providing much evidence or follow up.

Congress president Diosdado Cabello said in a television broadcast that 11 soldiers were among those implicated, including a retired general, and that several had been arrested.

He also named two opposition politicians and a businessman as plotters and charged that the U.S had tried to buy the loyalty of air force officers.

Cabello showed photos of weapons and other items that he said had been seized from those implicated. In addition to the palace, the plotters planned to bomb the Defense Ministry and the headquarters of the government-sponsored news channel Telesur, officials charged.

On Friday, the military's top leadership denounced the purported coup in a nationally televised news conference.

Opposition coalition spokesman Jesus Torrealba rejected the claim of a plot.

'The government makes up these stories about coups to avoid talking about how the country is breaking down,' he told a group of journalists.

Government opponents also complained about what they said is the continuing harassment of opposition leader Leopoldo Lopez, who has been jailed since last February for his role in leading protests that resulted in more than 40 deaths.

An opposition demonstrator prepares to throw a molotov cocktail at police after clashes broke out at a protest in Caracas on Thursday as Venezuelans marked the anniversary of last year's bloody protest movement

His party, Popular Will, said more than 10 masked men violently raided Lopez's cell early Friday and moved him to an isolation cell as punishment.

Human Rights Watch condemned the 'violent attack' and said what it considered reliable sources had confirmed the authenticity of the opposition's account.

The Associated Press could not verify the raid, and the government declined to comment.

U.S. State Department spokeswoman Jen Psaki also criticized the government's plot charge, calling the accusation 'ludicrous' and saying it was part of a pattern by Venezuela's government of looking for scapegoats as the country's struggles with severe economic problems.

'These efforts reflect a lack of seriousness on the part of the Venezuelan government to deal with the grave situation it faces,' she told reporters in Washington.

A study by the Caracas-based newspaper Ultimas Noticias counted 63 allegations of assassination plots from the beginning of the late Hugo Chavez's presidency in 1999 and his death in 2013. The government of Chavez's successor, Maduro, has denounced more than a dozen purported plots since coming to power 15 months ago.

Last spring, Maduro announced that three air force generals had been arrested after they were discovered plotting with opposition politicians to overthrow the government. Officials have said nothing about the case since.

The most serious recent allegation came in late May, as authorities tried to mop up dissent that led to a three-month wave of deadly anti-government protests.

Top officials delivered an hours-long presentation in which they accused a handful of opposition leaders of working with the U.S. ambassador in neighboring Colombia to 'annihilate' Maduro.