Two people were killed and 90 wounded in street clashes on Wednesday, June 26 between supporters and opponents of Egypt's Islamist president in the city of Mansoura, security sources said, hours before Mohamed Mursi is to address the nation, according to Reuters.

There were also clashes in the neighboring Nile Delta city of Tanta, north of Cairo, though casualty figures from there were not immediately available.

Mursi is due to make a keynote speech in Cairo in a few hours to address calls for his resignation. Major opposition rallies are planned for the weekend, which some fear could turn violent.