The remains of a police car set on fire is guarded by riot police in downtown Toronto, Canada, during the G20 summit Saturday, June 26, 2010. Photograph by: Kier Gilmour , Canwest News Service

TORONTO -- The number of protesters arrested has climbed to more than 300 and officers expect more arrests will be made following a riot early Sunday morning.

By 6:15 a.m., police said more than 300 people have been charged and a long line of protesters were also waiting to be processed, said Integrated Security Unit spokesman Wendy Drummond.

She said each protester would face a variety of charges, and could be held in custody depending on their violations and criminal history.

Only about 40 arrests were made between 6 a.m. and 4 p.m. Saturday, but by 3 a.m. Sunday, the ISU confirmed arrests of more than 200 protesters who rampaged through the city's downtown core all day Saturday and into Sunday.

Drummond told Canwest News Service that she was aware of more "people who want to go beyond the peaceful protest and have violence."

"We will continue to support those who protest peacefully in the downtown core today, but these groups that committed these criminal acts are not protesters. Do not associate yourself with them if your intent is to not commit criminal offences," she warned the public.

"We are in it for the long haul," she said. The ISU is composed of thousands of officers from across the country.

Drummond said police have used ARWEN launchers, which shoot a special kind of bean bag or plastic projectiles, and tear gas against protesters.

There are reports that a large group of protesters wearing backpacks and balaclavas were marching near Queen St. East and River Street by 2 a.m.

A crowd of about 200 people chanted outside the Eastern Avenue temporary G20 detention centre nearby.

A small group of black-clad protesters were surrounded at a downtown intersection around 10 p.m. ET Saturday.

A police line in full riot gear began marching at the group, banging their batons on their shields, in hopes of preventing more protesters from moving towards the G20 security fence still located blocks away.

The mood was tense as a small number of protesters yelled obscenities. Helicopters could be heard overhead.

The officers loudly chanted: "Move, move," as they marched.

One older man was pushed by police out of the way as he was seeking shelter from the pouring rain.

Police were telling everyone to "leave the area," but few were going.

This surround-and-disperse-the-crowd tactic was used many times by police Saturday.

The day began peacefully but by midafternoon, anarchists hiding within the 10,000 or so protesters stepped things up, hurling objects such as golf balls, burning police cars and smashing windows, then darting away - sometimes to change out of their black garb in an effort to throw police off.

Holding them off were some 5,500 police officers in full riot gear and on horseback who made repeated charges at the rioters in an effort to push them northwards and away from the downtown core where the leaders of the G20 have gathered for their annual summit.

As the night wore on, police continued to make arrests, darting forward into the crowds to grab rioters and pull him them back behind police lines. The Integrated Security Unit confirmed that 130 arrests were made as of 9:30 p.m. ET on Saturday.