CAIRO: Overnight clashes between police and residents of a densely populated district just north of Cairo have left four people dead and 12 wounded, The Health Ministry said on Sunday.

Security officials said the clashes began when a bystander in Shubra al-Kheima was hit by a stray bullet fired by police chasing a suspected drug dealer. The bystander, identified by the officials as Mahrous Mohammed Mahrous, was hit in the head as he sat on his apartment's balcony.

The clashes began on Saturday night and continued until Sunday, with protesters using rooftops near the local police stations to fire at policemen and shower them with rocks. Police replied with tear gas.

The Health Ministry said in a statement that the 12 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 under Mubarak's 29-year rule was one of the major causes of the 2011 uprising.

Police have yet to fully return to their duties since they abandoned their posts early in the 2011 uprising. Since then, insufficient police presence has contributed to Egypt's worst crime wave in living memory, with thefts and break-ins particularly rampant.

In the latest such crimes, the security officials said gunmen on Sunday raided a post office in the Nile Delta town of Kafr el-Dawar, killing a police guard before making away with 2 million pounds (around $300,000).

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