About 300 people were arrested and 20 were injured during overnight protests in Montreal in defiance of Quebec's contentious Bill 78, which cracks down on student-stoked demonstrations sparked by the province's proposed tuition hikes.

Ten police officers and 10 civilians suffered minor injuries in the latest protest. One person was taken to hospital with a serious head injury that emergency services called "non-life-threatening."

Just before midnight on Sunday, about 5,000 people gathered in the streets in the heart of the city's Latin Quarter, alternating between cacophonous cheering and chanting.

"Devrait pas nous fâcher," they yelled — "You shouldn't get us mad."

For the 27th night in a row in the city, marchers gathered near the University of Quebec in Montreal (UQÀM) and then headed to the heart of downtown.

Police declared the demonstration illegal under the province's new student-crisis law, adopted Friday, as soon as it began around 9 p.m. ET.

The law makes it illegal to hold a rally of more than 50 people without consulting at least eight hours ahead of time with police about its route and timing.

Montreal police said on Twitter that "illegal acts" were committed from the start. They alleged that some people threw things at police on bicycles, while others wore face masks, flouting a recently passed municipal bylaw that bans them during protests.

Constables ordered the demonstrators off the streets and onto sidewalks, but the commands were largely ignored.

Dozens arrested

Two journalists were swept up and arrested as ranks of riot police surrounded a group of protesters near the intersection of St. Laurent Boulevard and Ontario Street. One of the reporters was wearing a ski mask to protect against police chemical irritants, and was lightly injured in the fray.

Both were held for 20 minutes and told by a police officer that he "didn't give a f—k" they were journalists, before being let go, according to La Presse.

Provincial police were called in for the second night in a row, as were officers on horseback. In various parts of downtown, constables fired tear gas and muzzle blasts at crowds.

What began months ago as a student strike against the Liberal provincial government's plan to hike tuition fees by 70 per cent over the next five years has ballooned into a broader social movement supported by several of Quebec's major labour, environmental and political groups.

The movement picked up some celebrity backing in the last few days, with documentary filmmaker Michael Moore and Montreal band Arcade Fire lending their support.

Moore is calling Quebec's student movement "amazing," and on Sunday tweeted: "Canadians are in revolt in Quebec over new gov't law limiting democratic rights. No news of it in US press. Their uprising is inspiring #ggi."

Videos dencouncing bill released

The student movement's most popular hashtag is #ggi (grève générale illimitée, French for general unlimited strike.)

The international hacker collective Anonymous has also taken an interest in the growing Quebec movement.

One of the collective's Twitter accounts tweeted "Goodbye Quebec. Hello Quebecistan," and warned of future actions against the Quebec government.

The group, which regularly hacks into government websites around the world, also released two videos denouncing Bill 78 and planned tuition increases.

"Resistance is futile," a computer-modulated voice stated in one video. "The hour of war has come."

The website for the Quebec Liberal party and the province's Education Ministry were down for portions of the weekend in an apparent cyberattack. Anonymous, however, did not claim responsibility.

Student organizers estimate that 150,000 college and university students are still on strike.