Riot police fired tear gas and clashed with protesters early Saturday as anger boiled over once more in the Missouri suburb where an officer shot dead an unarmed black teenager a week ago.

Riot police fired tear gas and clashed with protesters early Saturday as anger boiled over once more in the Missouri suburb where an officer shot dead an unarmed black teenager a week ago.

The renewed unrest came hours after police said Michael Brown, 18, had been the suspect in a robbery at a convenience store in the St. Louis suburb of Ferguson, minutes before a policeman shot him dead.

Police also named the white officer involved in the shooting in the majority black area, but after a calm Thursday night, the announcements served only to ratchet up tensions again, with people targeting shops, reportedly including the one where Brown carried out the alleged robbery on August 9.

Three stores were looted in the fresh disturbances that also saw Molotov cocktails lobbed at police, CNN said from Ferguson, but there were also reports that locals, some armed, had stepped in to stop shops being ransacked.

Police -- who have been accused of a heavy-handed response -- retaliated with tear gas, smoke bombs and rubber bullets, but they mostly stayed at a distance in armored vehicles and riot gear, news reports said.

"If you're getting conflicting reports, it's because there's chaos here. It's dead in some areas, crazy in others.#Ferguson," wrote BuzzFeed reporter Joel Anderson on Twitter.