Port Said prosecution ordered on Wednesday the detention of 15 defendants who are accused of instigating clashes over the past week.

The defendants were deported to a public prison in Damietta on Saturday where they will be detained for four days pending investigations.

The prosecution accused the defendants with "vandalizing public property, theft, killing two police officers and attacking police installations."

Investigations were conducted amid tight security to protect the courts' complex in Damietta.

Violence erupted in Port Said after a court sentenced to death 21 defendants accused of involvement in killing 74 people during football riots last February.

President Mohamed Mursi on Sunday imposed a curfew from 9 p.m. to 6 a.m. and declared a state of emergency in Port Said, Suez, and Ismailia for 30 days.

Over 40 people were killed and 630 were injured as a result of the violence since Saturday.