A police helicopter has dropped grenades on Venezuela’s Supreme Court building and fired shots at the interior ministry in what President Nicolas Maduro called a “terror attack” against his government.

Information minister Ernesto Villegas said the stolen helicopter first fired 15 shots on the ministry in Caracas, the capital, as a reception was taking place on Tuesday.

It then flew a short distance to the Supreme Court building and dropped four grenades, two of them near the national guardsmen protecting the building.

Maduro said no one was injured as the grenades failed to detonate during the incident.

The attack occurred as Maduro was speaking live on state television to journalists gathered at the presidential palace.

“I have activated the entire armed forces to defend the peace,” he said.

However, opponents on social media 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.

Maduro has been facing three months of opposition protests and some dissent from within government ranks.

An Associated Press news agency reporter heard gunfire as a helicopter buzzed over downtown Caracas but was unable to confirm where the shots were being fired from.

Call For Rebellion

Around the time of the attack, a video appeared on social media in which a police squad pilot, identified as Oscar Perez, called for a rebellion against the Maduro’s “tyranny”.

“We have two choices; be judged tomorrow by our conscience and the people or begin today to free ourselves from this corrupt government,” he said.

Perez read his statement with four people dressed in military fatigues, ski masks and carrying assault rifles standing behind him.