Egyptian authorities have bolstered security around key installations as a preliminary death sentence against former Islamist President Mohammed Morsi and more than 100 other people sparked attacks on the judiciary. Hours after a Cairo criminal court sentenced Morsi on Saturday, three judges were shot dead in the city of El-Arish, in the north of the Sinai Peninsula, state media reported. Morsi supporters from the outlawed Muslim Brotherhood set fire to a court in Sadat City, 90km northwest of Cairo, state-run website Ahram Gate reported.A bomb exploded outside a courthouse in the city of Assiut late on Saturday, wounding a police officer, and another exploded yesterday in Port Said, wounding an officer.The verdicts raise tensions in a country mired in unrest and struggling to revive its economy, which had been depressed since before the military ousted Morsi in 2013, a year after he became Egypt's first freely elected civilian president.International rights groups, which say President Abdel-Fattah El-Sisi is curbing freedoms, denounced the court ruling, and Brotherhood leaders urged followers to stand firm against the government."This coup will fall," Salah Abdel-Maksoud, who served as information minister under Morsi, said on Al-Jazeera TV news channel.He urged: "Confront the coup using peaceful means."Morsi was toppled by the military in response to popular demands to end his rule. Since the ousting the authorities have waged a crackdown on the Brotherhood , killing hundreds and arresting and charging thousands. A number of mass death sentences have been handed down but many have been commuted.Prison officials said six members of Ansar Beit al-Maqdis, an extremist movement linked to Islamic State, were hanged, Ahram Gate reported yesterday. The government blames the group, along with the Brotherhood, for attacks on its security forces in north Sinai.Morsi and other Brotherhood leaders face a string of charges. He was sentenced last month to 20 years in prison in connection with violence near the presidential palace during a protest against his rule. He remains on trial on other charges, including insulting the judiciary and spying for Qatar.More than 100 other Islamists were given the death penalty on Saturday, including prominent Qatar-based Egyptian cleric Yusuf al-Qaradawi, who is viewed as the Brotherhood's spiritual leader.Some of those sentenced in the Cairo court were members of Hamas, the Palestinian militant group that rules Gaza. The group said on its website that some of the convicted were dead and others are in Israeli prisons.Egypt's State Information Service defended the government against its detractors, saying the criticism reflected "ignorance and lack of accuracy"...