CAIRO: The Health Ministry says 11 people have died in clashes between security forces and protesters loyal to toppled President Mohammad Mursi.

Tuesday's violence comes as a two-day referendum begins on a new constitution that, if adopted, would replace an Islamist-tilted charter approved under Mursi's rule. Mursi was ousted in a popularly backed coup last July.

The ministry says the deaths occurred in Cairo, the adjacent province of Giza and two provinces south of the capital, Bani Suef and Sohag. The statement says 28 people also have been wounded.