Venezuela National Assembly stormed by Maduro supporters
About 100 government supporters have burst into Venezuela's opposition-controlled National Assembly, where they beat up several lawmakers.
Witnesses said the confrontation came after an assembly session to mark the country's Independence Day.
Military police guarding the site stood by as intruders brandishing sticks and pipes broke through the gate, AFP news agency said.
The government has vowed to investigate.
"I will not be complicit in acts of violence," said President Nicolás Maduro.
About 350 people were besieged for hours, including journalists, students and visitors, according to the assembly's speaker Julio Borges.
Mr Borges also named five of the lawmakers injured. Some were taken away for medical treatment, including Deputy Américo De Grazia, who was carried out on a stretcher.
Venezuela has been shaken by often violent protests in recent months and is in economic crisis.
"This does not hurt as much as seeing every day how we are losing our country," deputy Armando Armas told reporters as he got into an ambulance, his head swathed in bloody bandages.
The US state department condemned the violence, calling it "an assault on the democratic principles cherished by the men and women who struggled for Venezuela's independence 206 years ago today".
AFP, whose journalists were at the scene, said reporters were ordered to leave by the attackers, one of whom had a gun.
Before the intruders rushed the building, Vice-President Tareck El Aissami made an impromptu appearance in the congress with the head of the armed forces, Vladimir Padrino López, and ministers.
Mr El Aissami gave a speech urging the president's supporters to come to the legislature to show support for him.
A crowd had been rallying outside the building for several hours before breaking into the grounds.
A statement from the the ministry of communication said, the government had ordered an investigation "to establish the whole truth, and on that basis, to apply sanctions to those responsible".
What's happening in Venezuela?
- The country is in a deep economic crisis, made worse by the falling price of oil, which accounts for about 95% of its export revenues and was used to finance some of the government's generous social programmes. Forced to make cuts, Mr Maduro has seen his support fall among core backers
- Also, as a result of the crisis, parts of Venezuela face severe shortages of basic supplies such as medicine and food
- The opposition accuses Mr Maduro of not only mismanaging the economy but also eroding the country's democratic institutions
- In March, the Supreme Court decided it would take over the National Assembly. The decision was reversed, but Mr Maduro was accused by opponents of trying to stage a coup. That sparked almost daily protests calling for his resignation
- Meanwhile, Mr Maduro says the opposition is trying to overthrow his government illegally, and blames the country's problems on an "economic war" being waged against him
Just hours before, the attorney general was facing suspension for refusing to appear in court.
Luisa Ortega Díaz has been accused of committing errors in her job, but critics believe she is being targeted after speaking out against the president's reform plans.
Last week, she also criticised Mr Maduro after an incident in which a stolen police helicopter flew over Caracas, dropping grenades and firing shots.
The president called it a "terrorist attack" but Ms Ortega said the country was suffering from "state terrorism".
While Venezuelan security forces later found the abandoned helicopter near the coast, parliamentary speaker Julio Borges said there was a possibility that the incident was a hoax.
On Tuesday, the fugitive policeman who piloted the helicopter, Oscar Pérez, posted a video online saying he was still in Caracas.
He urged Venezuelans to stand firm in the streets in protests against the president.