Thousands of angry demonstrators destroyed the headquarters of Egypt's ruling party in this northern Sinai town in the second day of protests demanding better security, police and witnesses said.
Dozens were injured in clashes when plainclothes police officers attacked the demonstrators with batons, tear gas and metal chains.
The demonstrators, who were protesting what they say is a lack of adequate security from Egyptian authorities, pulled down murals of President Hosni Mubarak from the National Democratic Party's building and set furniture and documents on fire, said Hassan Abdullah, an opposition party member in El-Arish who was at the scene.
Police officials in Cairo confirmed that the NDP building was destroyed and furniture and other items set on fire. The officials spoke on condition of anonymity because they were not authorized to speak to the media.