Mario Balotelli's arrival at AC Milan has been marred by violent scenes as fans clashed with police outside a restaurant where he was dining.
Milan supporters let off flares and threw bottles outside the establishment, forcing officers to use tear gas to control the crowd.
One police officer was take to hospital with a head injury that is not thought to be serious, the Daily Mail reports.
Balotelli is currently undergoing a medical with the Italian giants ahead of a proposed transfer from Manchester City worth an initial £19m.
The Italy international joined the Premier League champions from Milan's city rivals Inter Milan for £24m in 2010.