More than a million Brazilians poured into the streets of at least 80 cities Thursday in this week's largest anti-government demonstrations yet, protests that saw violent clashes break out in several cities as people demanding improved public services and an end to corruption faced tear gas, pepper spray and rubber bullets.

At least one protester was killed in Sao Paulo state after a car rammed into a crowd of demonstrators, the driver apparently angered about being unable to drive along a street.

In Rio de Janeiro, where an estimated 300,000 demonstrators swarmed into the seaside city's central area, running clashes played out between riot police and clusters of mostly young men, their T-shirts wrapped around their faces. But several peaceful protesters were up in the crackdown, too, as police fired tear gas canisters into their midst and at times indiscriminately used pepper spray.

Thundering booms echoed off stately colonial buildings as rubber bullets and the gas were fired at fleeing crowds.

At least 40 people were injured in Rio, including protesters like Michele Menezes, a wisp of a woman whose youthful face and braces belie her 26 years. Bleeding and with her hair singed from the explosion of a tear gas canister, she said that she and others took refuge from the violence in an open bar, only to have a police officer toss the canister inside.

It exploded on top of Menezes, tore through her jeans and dug out two quarter-sized holes on the back of her thighs while also perforating a rash of small holes in her upper arm.

"I was leaving a peaceful protest and it's not the thugs that attack me but the police themselves," said Menezes, removing her wire-rim glasses to wipe her bloodshot eyes.

She later took refuge in a hotel along with about two dozen youths, families and others said they had been repeatedly hit with pepper spray by motorcycle police as they too took refuge inside a bar.

Despite the crackdown, protesters said they would not back down.

"I saw some pretty scary things, but they're not going to shake me. There's another march on the 22nd and I'm going to be there," said 19-year-old university student Fernanda Szuster.

Asked whether her parents knew that she was taking part in the protests, Szuster said that "they know and they're proud. They also protested when they were young. So they think it's great."

She added, though, that she wouldn't tell her father the details of the police violence she was a victim of. "If he knew, he would never let me leave the house again."

In Brasilia, police struggled to keep hundreds of protesters from invading the Foreign Ministry, outside of which protesters lit a small fire. Other government buildings were attacked around the capital's central esplanade. There, too, police resorted to tear gas and rubber bullets in attempts to scatter the crowds.

Clashes were also reported in the Amazon jungle city of Belem, in Porto Alegre in the south, in the university town Campinas north of Sao Paulo and in the northeastern Brazilian city of Salvador.

"This was meant to be a peaceful demonstration and it is," said artist Wanderlei Costa, 33, in Brasilia. "It's a shame some people cause trouble when there is a much bigger message behind this movement. Brazil needs to change, not only on the government level, but also on the grass roots level. We have to learn to demonstrate without violence."