A brawl between two groups of immigrants in central Athens yesterday afternoon escalated into chaos following police intervention, resulting in at least 11 injuries. The riot, which reportedly involved mostly African immigrants, many of whom were wielding knives, axes, machetes and swords, led to one officer being knifed, an immigrant being shot in the leg and a passerby being injured by a ricocheting bullet. Police believe the standoff, near the junction of Sophocleous and Menandrou streets, had been planned by the two groups and may have regarded a dispute over drugs or a protection racket. Officers had detained some 56 of the migrants involved in the incident by late last night for questioning to determine the cause of the brawl and press charges against the assailants. The attempt by police to intervene in the brawl prompted a violent reaction from one Somalian man who attacked an officer with a knife in one hand and an ax in the other, according to witnesses. The policeman, who sustained minor injuries, fired at the immigrant during the scuffle, grazing his leg. The bullet subsequently hit a passerby, causing minor injuries. «A group of Africans squared up against a group of Iranians and other nationalities and all hell broke loose,» one witness told Antenna television channel. Another bystander said that one of the participants in the brawl had two swords strapped onto his back. Police seized dozens of knives, axes, swords and iron bars as well as long blades believed to have been stolen from paper factories.