Islamists massed for further protests yesterday to demand the army restore Egypt's first democratically elected leader, after 24 hours of ferocious violence that killed 37 people and injured more than 1,000 nationwide.

The atmosphere was tense as interim leader Adly Mansour held talks with ministers, aides and the Tamarod rebel group that engineered the mass demonstrations culminating in the ouster of Islamist president Mohamed Morsi.

Crowds were swelling late afternoon outside Cairo's Rabaa al-Adawiya mosque, where Morsi supporters have been camped out for 10 days.

A nearby bridge was still littered with rocks and burned out tyres from the overnight confrontations.

Anti-Morsi protesters meanwhile set up checkpoints in Cairo's iconic Tahrir Square after a night of deadly fighting nearby.

A coalition of Islamist groups early yesterday vowed "civilised protests and peaceful sit-ins in Cairo until the military coup is reversed and the legitimate president is restored".