The Venezuelan military is hunting for a rogue elite police officer suspected of carrying out a helicopter attack on the country's Supreme Court.
Oscar Pérez posted Instagram videos admitting the attack and calling on Venezuelans to rise up against the government of President Nicolás Maduro.
The officer's home has been searched as the president put the entire military on alert, citing a "terrorist attack".
The country is in the midst of a deep economic and political crisis.
Nobody was injured in the helicopter attack, which took place at around sunset on Tuesday evening.
One police source reported by Reuters said that the helicopter had been dumped in Higuerote, on the Caribbean coast, but that the pilot had not been found. The report has not been verified.
What happened in the attack?
A blue police helicopter was seen flying over central Caracas carrying a banner reading "350 Freedom" - a reference to a clause in the constitution cited by opponents of Mr Maduro to claim his government is illegitimate.
The helicopter, reportedly stolen, carried the marks of the CICPC forensic police force, for which Oscar Pérez has worked for 15 years.
Images on social media showed two occupants, one masked.
The government said 15 shots were fired at a social event at the interior ministry. The helicopter then flew to the court and dropped four Israeli-made grenades of "Colombian origin". One failed to detonate. No-one was injured.
Many of those opposed to Mr Maduro see the Supreme Court as one of his main supporters.
Who flew the helicopter?
The police officer identified himself as Oscar Pérez in the Instagram video statements.
Appearing in military fatigues and flanked by armed, masked men in uniform, he appealed to Venezuelans to oppose "tyranny".
"We are a coalition of military employees, policemen and civilians who are looking for balance and are against this criminal government," he said.
"We don't belong to any political tendency or party. We are nationalists, patriots and institutionalists."
He said the "fight" was not against the security forces but "against the impunity of this government. It is against tyranny".
Mr Pérez is a colourful character, judging by his posts on social media.
He is pictured brandishing a high-calibre weapon while scuba-diving, and in another video shows off his gun skills by shooting a target over his shoulder, using only a make-up mirror as a guide.
He also appeared in the 2015 Venezuelan movie, Suspended Death, which tells the story of elite police officers rescuing the victim of a kidnapping.
How has the government responded?
President Maduro appeared on state television to denounce the attack.
He said: "I have activated the entire armed forces to defend the peace. And you can be assured that sooner or later, we are going to capture that helicopter and those that carried out this terror attack against the institutions of the country."
Defence Minister Vladimir Padrino López urged Venezuelans to remain calm and stay vigilant.
State TV showed images of the pilot in front of the US Capitol building in Washington.
Mr Maduro has long claimed the US government is attempting to have him overthrown.
And the opposition?
Some of the president's opponents took to social media to suggest he was responsible for staging the helicopter attack in order to justify a further crackdown on dissent.
Julio Borges, leader of the opposition-controlled legislature, said: "It seems like a movie. Some people say it is a hoax, some say it is real, some say that it was police personnel who really are fed up.
"I summarise it like this: a government is decaying and rotting, while a nation is fighting for dignity."
Freddy Guevara, of the opposition MUD alliance, posted a tweet on Wednesday calling on people to continue to oppose the Maduro government.
He said: "Maduro knows that nobody supports him, so today more than ever we must continue in the street, generating pressure to overcome this dictatorship!"
Could this have been a coup attempt?
President Maduro has often alleged attempts to unseat him, and was quick to suggest this was another, but it is unclear how much support the police officer has.
He said the pilot had previously worked for former Interior and Justice Minister Miguel Rodriguez Torres, who the president has accused of links to the CIA.
Mr Rodriguez Torres quickly denied any involvement, saying he was "not convinced" by the helicopter event.
"Conclusion? A cheap show. Who gains from this? Only Nicolas, for two reasons: to give credibility to his coup d'etat talk, and to blame [me]," he said.
The wider picture in Venezuela?
There have been almost daily anti-government protests in Venezuela for more than two months as the country's economic and political crisis worsens.
Those opposed to the government say they are determined to keep protests going until fresh elections are called and the government is ousted.
More than 70 people have been killed in protest-related violence since 1 April, according to the chief prosecutor's office.