Two people were killed and another 20 injured in clashes between supporters and opponents of toppled president Mohamed Morsi across Egypt on Friday, Xinhua news agency reports local media as saying.

A 12-year-old boy in Giza was among those killed and 20 civilians were injured in the governorate as well as Sharqiyah and Beheira, reports said.

Security forces dispersed protestors in Giza's Omraniya district where the crowd blocked roads with ignited tires.

In the canal city of Suez, Morsi's supporters clashed with his opponents and security forces which led to at least four people injured including one in critical condition.

Protests also took place in other governorates including Cairo, Alexandria after the Muslims' Friday noon prayer with some ending in clashes.

In the northern coastal city of Alexandria, Morsi's supporters protested in the district where the ex-president is reportedly detained and in Sidi Bishr district.

Security forces arrested 12 protesters in the two districts and elsewhere three people were injured in Sharqiya and another in Beheira.

Police arrested in total 19 Muslim Brotherhood members in Friday's clashes.

The pro-Morsi National Coalition to Support Legitimacy called for demonstrations on Friday under the name of "Egypt's women are a red line" in reference to the recent arrests of women protesting in support of Morsi.

Morsi's trial for charges of killing protesters during his one-year rule began on Monday but the judge postponed it to Jan 8 next year.