Five opposition members of parliament were taken to hospital following the attack by about 100 supporters of President Nicolas Maduro, who were armed with metal pipes, wooden sticks and clubs.
Two employees of the assembly were also reported to have been injured in the assault, which left people with blood pouring from their heads and the walls stained with blood.
Seven politicians are hurt, as a mob of around 100 pro-government militants storm the National Assembly, in Caracas, Venezuela
The government building is the only state institution still nominally controlled by the opposition
Government backers smash up a car before rushing the congress
Supporters of President Maduro broke through the front gate and crossed the interior gardens
Armed with metal bars and wooden sticks, attackers left victims with blood pouring from their heads
Firecrackers were set off, creating panic and fear among the opposition
Two employees of the assembly were also reported to have been injured in the attack
People rush to put out fires caused by concussion grenades
Masked militants force their way inside the corridors of the congressional building
An injured and shirtless government supporter is restrained by security forces
Opposition lawmaker Luis Stefanelli (C) grabs the bloodied militant
A member of the National Guard amid the smoke and chaos
The attack took place on Wednesday – Venezuela’s independence day – marking 206 years of the country’s independence from Spain.
Government backers broke through the front gate, crossing the interior gardens before reaching the corridors of the congressional building.
One man was reported to be carrying a gun, and concussion grenades and firecrackers were set off, creating panic and fear among the opposition.
Following the attack, around 350 people were trapped in the National Assembly during a nine-hour siege.
While military police initially stood by, the siege was finally brought to an end when officers and soldiers stepped in to form a cordon, allowing people to safely exit the building.
The National Assembly is the only state institution still nominally controlled by the opposition, who want to see President Maduro removed from power.
Mr Maduro condemned the attack, saying: “I will never be complicit in any act of violence.”
The US State Department called the attack “an assault” on Venezuela’s “democratic principles”.
This attack is just the latest violent outburst in a series of anti-government protests, which have killed 91 people since April.
Protesters blame Mr Maduro for the country’s economic crisis, while he insists the chaos is the result of a US-backed capitalist conspiracy by the opposition.
President Maduro – who has the support of the military – is now planning to set up an assembly to rewrite the constitution, a move the opposition say is calculated to keep him in power.
Last month, a Venezuelan police officer and film star in a helicopter dropped four grenades on Venezuela’s supreme court before opening fire on the interior ministry, in a protest against what he called a “tyrannical” government.
In a video released on Wednesday, Oscar Perez urged the security forces to turn on Mr Maduro.