TORONTO – Black-clad protesters broke off from a crowd of peaceful demonstrators protesting the G-20 global economic summit in Toronto, torching police cruisers and smashing windows with baseball bats and hammers. Police arrested more than 150 people.

Police with shields and clubs earlier pushed back another small group of demonstrators who tried to head south toward the security fence surrounding the Group of 20 summit site. Some demonstrators hurled bottles at police.

“This isn’t our Toronto and my response is anger,” Toronto Mayor David Miller told CP24 television. “Every Torontonian should be outraged by this.”

A stream of police cars headed to Toronto to reinforce security there after the smaller Group of Eight summit ended in Huntsville, Ontario. The vandalism occurred just blocks from where President Obama and other world leaders were meeting and staying.

“These images are truly shocking to Canadians,” Canadian Public Safety Minister Vic Toews said in a statement. “We are taking all measures necessary to ensure Canadians, delegates, media and international visitors remain safe.”

Previous major world summits also have attracted massive, raucous and sometimes destructive protests by anti-globalization forces.

The roving band of protesters in black balaclavas shattered shop windows for blocks, including at police headquarters, then shed some of their black clothes, revealing other garments, and continued to rampage through downtown Toronto.

Protesters torched at least three police cruisers in different parts of the city, including one in the heart of the city’s financial district.

One protester jumped on the roof of one before dropping a Molotov cocktail into the smashed windshield.

Police in riot gear and riding bikes formed a blockade, keeping protesters from approaching the security fence a few blocks south of the march route. Police closed a stretch of Toronto’s subway system along the protest route and the largest shopping mall downtown closed after the protest took a turn for the worse.

Dozens of police officers later boxed in demonstrators from both sides of a street in a shopping district. The protesters encouraged the media to film it and they sang “O Canada,” Canada’s national anthem, before being allowed to disperse.