A dozen protesters were arrested as trouble flared during a controversial demonstration by anti-Islam campaigners.
Several “disorders” were dealt with by riot officers as more than 800 English Defence League supporters gathered in Aylesbury, Thames Valley Police said.
Demonstrators were believed to have hurled coins, glass bottles, plastic flag sticks and cans at officers.
Officers, who dealt with a surge against police lines in the Market Square, made 12 arrests, including eight for possessing offensive weapons.
The EDL protest presented a “major challenge for the town”, officers said.
The organisation, which describes itself as “a counter-Jihad movement”, has held several demonstrations in recent months in Manchester, Bolton and Dudley.
Members of Unite Against Fascism (UAF) attended the event to voice their opposition.
Aylesbury Superintendent Richard List said: “We are a tolerant, successful and proud town – we all need to remember our tremendous strengths at this difficult time. I would like to express my sincere thanks to you all.”