Egyptian security sources say police fired tear gas and arrested more than 20 people to break up an open-air prayer meeting of the banned Muslim Brotherhood.
The clashes erupted when several hundred people gathered Saturday in the Nile Delta village of El-Salhiya for prayers to celebrate Eid al-Fitr, which marks the end of the Muslim holy month of Ramadan.
Witnesses say police intervened to prevent the service from behind held outside, where Muslims normally pray during Eid al-Fitr.
Brotherhood members reacted by throwing stones at security forces.
Egypt's government has detained many Brotherhood members in recent months as part of a crackdown on the group.
The Muslim Brotherhood, an Islamist group, has been banned in Egypt for more than 50 years, but its members run for political office as independents.
The group controls about one-fifth of the 454 seats in Egypt's lower house of parliament.
The Muslim Brotherhood says it wants to transform Egypt into an Islamic state through democratic reforms.
Some information for this report provided by AP, AFP and Reuters.