UPDATE: TORONTO -- More than 500 people have been arrested in Toronto after a night of rioting that saw police cars burned in the financial district and storefront windows broken as leaders of the world's largest economies gathered in the city for the G20 summit.

As clashes between police and protesters moved into their second day, there were more reports of journalists and peaceful protesters being arrested. The National Post reported that two of its photographers were arrested, and a Post blogger says a cyclist was arrested after accidentally bumping into a police officer.

Meanwhile, the UK's Guardian confirmed earlier reports that one of its freelance journalists, Jesse Rosenfeld, was beaten and arrested at a protest Saturday night (see below).

The arrested protesters are being held in cages at a converted film studio on the city's downtown east side. News reports indicate that, so far, none of the arrested have been let go. The Globe and Mail reports that about 100 peaceful protesters converged on the facility Sunday, chanting "let them go."

As they stood outside the gate to the facility, at least two vans pulled up. Officers in plain clothes jumped out of the van and arrested a few protesters. Others began fighting back. A tense stand-off ensued as a bus with officers in riot gear pulled up to the scene.

Police grabbed some protesters out of the crowd, throwing them to the ground and dragging them away. Others streamed away from the area, crying. Three stood nearby consoling each other and hugging.

A woman who said she was arrested while peacefully protesting yesterday described the conditions inside the detention facility to CTV. She said protesters were housed in cages, some without benches.

A video posted to YouTube shows police in riot gear attempting disperse a non-violent protesters at Queen's Park, next to the provincial legislature, on Saturday. Officers can be seen grabbing protesters out of the crowd and assaulting them.

ORIGINAL STORY FOLLOWS BELOW VIDEO

The following video was posted to YouTube by user forzaferrarif1fan.

TORONTO -- Reporters covering the G20 summit in Toronto say they were the target of police violence overnight, as riots blamed on anarchist groups left four police cars burning in the financial district and resulted in the arrests of some 150 people.

"A newspaper photographer was shot with a plastic bullet in the backside, while another had an officer point a gun in his face despite identifying himself as a member of the media," reported the Canadian Press news agency. The agency did not say if it was its own reporters who were targeted.

Previously: Toronto gets ‘secret’ arrest powers ahead of G20 protests

In a remarkable series of Tweets early Sunday morning, journalist Steve Paikin of public broadcaster TV Ontario said he witnessed "police brutality" against a reporter and the arrests of peaceful demonstrators.

"I saw police brutality tonight. It was unnecessary. They asked me to leave the site or they would arrest me. I told them I was doing my job," he Tweeted.

"As I was escorted away from the demonstration, I saw two officers hold a journalist. The journalist identified himself as working for 'the Guardian.' He talked too much and pissed the police off. Two officers held him a third punched him in the stomach. Totally unnecessary. The man collapsed. Then the third officer drove his elbow into the man's back. No cameras recorded the assault. And it was an assault."

Paikin had been at a demonstration in Toronto's Esplanade neighborhood, a densely-populated area near the waterfront. He said police moved in on a crowd of peaceful, "middle class" protesters and began arresting them.

"Police on one side screamed at the crowd to leave one way. Then police on the other side said leave the other way. There was no way out," he Tweeted. "So the police just started arresting people. I stress, this was a peaceful, middle class, diverse crowd. No anarchists. Literally more than 100 officers with guns pointing at the crowd. Rubber bullets and smoke bombs ready to be fired. Rubber bullets fired."

Paikin, a respected journalist who has hosted national election debates in Canada, said he was "escorted" away by police before he could see how many people were arrested, "but it must have been dozens."

"I have lived in Toronto for 32 years. Have never seen a day like this. Shame on the vandals and shame on those that ordered peaceful protesters attacked and arrested."

Earlier in the day, police told media that a small group of "Black bloc" demonstrators broke off from a protest of 10,000 people and began smashing storefront windows along the city's trendy Queen Street.

The CBC News Network reported that protesters smashed in the windows of an American Apparel outlet, pulled out the mannequins and spread feces on the floor. The storefronts of McDonald's and Starbucks locations were also damaged, as were numerous bank branches.

Police shut down all public transit in the city center, including subway and streetcar lines. They also shut down a large downtown shopping complex after reports of looting. AFP reported that some 200 people were trapped inside, unable to leave after the mall was put into lockdown.

Watch: Protesters seize police car

"When the G20 protest began turning violent Saturday, police abandoned some of their police cars," reports the Toronto Star. "This one was briefly occupied on Queen Street."

The following video was shot by Jim Rankin of the Toronto Star.