The head of security in Port Said was sacked on Wednesday, security officials told AFP, as violence raged in the Egyptian canal city.
Mohsen Radi was relieved of his duties and transferred to the prison services department in Cairo "in response to demands by residents and to help calm the situation," one of the officials said.
Fresh clashes erupted on Wednesday in Port Said, the scene of several days of unrest, an AFP correspondent said.
Police and protesters lobbed rocks at each other under a volley of tear gas that caused several people to collapse. Gunfire could also be heard as military planes circled low overhead.
"Dirty government!" the protesters shouted as they ran to escape the thick tear gas.
Tension has been running high around the main security building in Port Said, which was set ablaze on Tuesday for the second day in a row.
The unrest in the Suez Canal city, fuelled by January death sentences handed down to football fans over deadly rioting last year, flared again on Sunday, with six people, including three policemen, dying in the clashes.