Violence broke out on Saturday night during a protest in northern London over last week's fatal shooting of a young man by police.
Some 300 people have gathered outside a police station in Tottenham to demand "justice" after 29-year-old private taxi driver Mark Duggan, a father of four, was killed in Thursday's shootout with police.
Protesters have been throwing petrol bombs at police officers, who have cordoned off the area. Two police cars, a double decker bus and nearby buildings have been set on fire.
Firefighters have been tackling the flames while police have been trying to prevent shops in the area from being looted.
Witnesses have described the situation as "chaos."
