CAIRO (AP) — Egypt’s Health Ministry says overnight clashes between police and residents of a densely populated district just north of Cairo have left four people dead and 12 wounded.

Security officials say the clashes began when a bystander was hit by a stray bullet fired by police chasing an alleged drug dealer. They began on Saturday night and continued until Sunday.

The ministry said in a statement that the wounded included two officers and a police conscript.

Clashes between police and civilians have been common since the ouster of autocratic leader Hosni Mubarak in an uprising nearly two years ago. Police brutality was one of the major causes of the 2011 uprising.

The officials spoke anonymously as they were not authorized to talk to the press.