Al-Gamaa Al-Islamiya spokesperson Mohamed Hassan has warned that violence could occur on 30 June, the anniversary of President Morsi's inauguration, because "there are domestic entities being funded from abroad that aim to stir chaos and make Egypt like Syria or Libya," London-based Al-Hayah reported on Friday.
"If the president is ousted, this will send Egypt into a cycle of violence and the law of the jungle will prevail," he predicted.
Muslim Brotherhood-allied forces might protest again after the Islamist 'renounce violence' protests on 21 June, Hassan added.
Such protests could prevent opposition protests on 30 June or mean bloodshed occurs, he noted.
Whether there will be more Islamist protests after 21 June will depend on developments on the street, the opposition's behavior and coordination among Islamist groups, he added.
Islamists will hold pro-government rallies to 'renounce violence' on 21 June.
Opposition protests on 30 June will demand the ouster of President Morsi and the holding of fresh elections.