Three judges were shot dead on Saturday in Egypt's North Sinai, hours after a court sentenced former Islamist president Mohammed Morsi to death over jailbreak charges.Gunmen attacked a car carrying the judges in El Arish city, also killing the driver and injuring another prosecutor, Xinhua news agency reported.Police rushed to the scene and started an investigation.No one has claimed responsibility for the attack.However, analysts say that it is more likely that the assault was carried out by the Sinai-based Ansar Bayt al-Maqdis, which has recently pledged allegiance to the Islamic State (IS) terrorist group.Earlier in the day, an Egyptian court sentenced Morsi and other Muslim Brotherhood leaders to death for a jailbreak incident in 2011, and also sentenced leaders of the outlawed group to death over charges of espionage with foreign powers to destabilize Egypt.Militancy escalated sharply in restive Sinai Peninsula after the ouster of Morsi by the army in response to mass protest against his one-year rule in 2013.Anti-government attacks have extended lately to reach the capital Cairo and other provinces across the country.