CAIRO (AP) — Egyptians have started voting on a draft for their country’s new constitution that represents a key milestone in a military-backed roadmap put in place after President Mohammed Morsi was overthrown in a popularly backed coup last July.

The two-day balloting, which began Tuesday, is a heavy blow to the Muslim Brotherhood’s campaign for the reinstatement of Morsi and paves the way for a presidential run by the nation’s top general.

A massive security operation is underway to protect polling stations and voters against possible attacks by militants loyal to Morsi.

Shortly before polls opened, an explosive device went off outside a Cairo courthouse. The blast damaged the front of the building but caused no casualties.

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