ISMAILIA, Egypt (REUTERS) - Hundreds of protesters broke into local government offices in the Egyptian city of Ismailia on Friday during demonstrations against President Mohamed Mursi, witnesses said, as violence between youths and the police flared in at least four cities.

Riot police fired teargas to try to break up the crowd that stormed the provincial governor's headquarters. Opponents of Mursi and his Islamist backers had earlier set ablaze the headquarters of the Brotherhood's political party in Ismailia.