Updated June 28, 2017 17:56:05

A Venezuelan police helicopter has launched a failed grenade attack on the country's Supreme Court in what President Nicolas Maduro condemned as terrorism.

The socialist leader, who has faced three months of opposition protests as well as dissent from within Government, said the helicopter shot at the judicial building and also threw some grenades that did not detonate.

Witnesses reported hearing several explosions in downtown Caracas, where the pro-Maduro Supreme Court, the presidential palace and other key government buildings are located.

The helicopter also buzzed over the Interior Ministry, Mr Maduro said in a televised speech to supporters, and was seen flying over the capital.

He said the nation's air defence was activated, thwarting what he called a "terrorist attack" and part of an ongoing coup attempt.

"It could've caused a tragedy with several dozen dead and injured," Mr Maduro said.

"We will capture the helicopter, and those who did this armed terrorist attack against the institutions of the country. I condemn this terrorist attack.

"I demand that the MUD [opposition coalition] condemns this eminently coup-mongering attack."

Photo: Venezuelan police squad pilot Oscar Perez has been accused of stealing the helicopter to launch the attack. (Instagram: oscarperezgv)

Communications Minister Ernesto Villegas said the attack was part of a "coup plot" and involved four grenades of "Colombian origin" fired from the "stolen" aircraft.

But there was also some speculation on social media among opposition supporters that the helicopter attack could have been staged to justify repression or cover up drama at Venezuela's National Assembly, where two dozen lawmakers said they were being besieged by pro-Government gangs.

Opponents have accused the President himself of trying to spread fear to help justify a crackdown against Venezuelans seeking to block his plans to rewrite the constitution.

Adding to the intrigue, pictures of a blue police helicopter carrying an anti-Government banner appeared on social media around the same time as a video in which a pilot for the police squad, identified as Oscar Perez, called for a rebellion against the Mr Maduro's "tyranny" as part of a coalition of members of the security forces.

"We have two choices: be judged tomorrow by our conscience and the people or begin today to free ourselves from this corrupt Government," the man said while reading from a statement with four people dressed in military fatigues, ski masks and carrying what look like assault rifles standing behind him.

Mr Villegas blamed Mr Perez for the attack, saying he took advantage of his role in the aerial transport department of CICPC — Venezuela's intelligence and investigative body.

Hugo Chavez launched a socialist revolution after he was elected in 1998, but under successor Nicolas Maduro, the oil-rich country has become a failing state.

Opposition leaders have long been calling on Venezuela's security forces to stop obeying a president they call a murderous dictator.

The Supreme Court is particularly hated by Mr Maduro's opponents for its string of rulings bolstering his power and undermining the opposition-controlled legislature.

Earlier on Tuesday, Mr Maduro warned that he and supporters would take up arms if his socialist government was violently overthrown by opponents who have been on the streets since April.

At least 75 people have died during several months of escalating unrest.

"We would never give up, and what couldn't be done with votes, we would do with arms, we would liberate the fatherland with arms," he said.

AP/Reuters

Topics: world-politics, unrest-conflict-and-war, venezuela

First posted June 28, 2017 12:02:30