London (CNN) -- British authorities urged for calm early Sunday, hours after demonstrators in north London burned police cars, and set a bus and buildings ablaze to protest the death of a local man. At least eight officers wounded in the protests were hospitalized, including one with a head injury, police said. The demonstrations started peacefully Saturday night when about 30 friends and relatives of the victim gathered outside Tottenham police station to protest his death. The protesters say the man, Mark Duggan, was shot by police Thursday. About three hours later, the protests turned tense when the crowd got bigger and started hurling projectiles and bottles at police cars, setting them ablaze, authorities said. "We did not have warnings that we were going to see the kind of disorder being witnessed tonight," said Cmdr. Stephen Watson. "We are aware of raised tensions in the community, which are understandable following the tragic death of Mark Duggan." Protesters pelted officers with bottles and bricks as police charged at the crowd and blocked off streets. A double-decker bus and some buildings in the area were also set ablaze, sending bright orange flames glowing in the night sky. "For those who involved themselves in this level of violence, there is no excuse," Watson said. Watson said the perpetrators may be brought to justice. But for now, the priority is to maintain calm.