http://www.bbc.co.uk/news/world-latin-america-40426642
Venezuela crisis: Helicopter launches attack on Supreme Court
Venezuela's Supreme Court has been attacked by grenades dropped from a helicopter in what President Nicolás Maduro called a "terrorist attack".
Footage on social media shows a police helicopter circling over the city before shots and a loud bang are heard.
The police officer said to have piloted the stolen aircraft issued a statement denouncing the "criminal government". His whereabouts are unknown.
Officials quoted by Reuters news agency said four grenades were dropped on the court and 15 shots had been fired at the interior ministry.
No injuries were reported but Mr Maduro said "a social event" had been taking place at the Supreme Court and the attack could have caused "dozens of deaths". One of the grenades failed to detonate, he added.
The police officer identified himself as Oscar Pérez in video statements posted on the social media platform Instagram.
Appearing in military fatigues and flanked by armed, masked men in uniform, he appealed to Venezuelans to oppose "tyranny".
Analysis: Will Grant, BBC News, in Mexico
It is generally an exercise in futility trying to predict if some new twist in Venezuela's long-running crisis is a "turning point" for the country.
There have been scores of seemingly decisive moments over the past few months - from the initial decision to strong-arm the national assembly, to the latest death of a teenage protester in Caracas - that quickly faded into the general malaise afflicting the oil-rich nation.
However, the sight of an apparently disaffected member of the security forces dropping grenades on the Supreme Court and allegedly firing on government buildings is extreme, even by Venezuela's standards.
Whether "Oscar Pérez" is indeed part of a coalition of like-minded "military employees, policemen and civilians" or just a rogue policeman is hard to say.
Certainly President Maduro was quick to dub the incident "a terrorist attack" and used it as a reason to "activate" the armed forces to keep the peace.
However, earlier in the day he, too, had thrown down the gauntlet to his opponents. "If the Bolivarian Revolution was at risk," he said, "what we couldn't do with votes, we would do with arms." The opposition in Venezuela took that as an overt threat.