A car bomb killed Egypt's top prosecutor Monday, destroying his convoy as he traveled to work in Cairo.
Hisham Barakat is the most senior state official killed in militant violence since the country's Islamist government was toppled two years ago.
Barakat led the prosecutions against figures from the Muslim Brotherhood and other Islamists, including former President Mohamed Morsi, who was ousted by the military in 2013.
The now-outlawed Muslim Brotherhood group has vowed to step up anti-government activities to mark the ouster of Morsi on June 30, 2013.
Monday's blast happened in the upscale Heliopolis district in eastern Cairo as Barakat was leaving his home. Officials say at least seven other people were wounded by the explosion, including guards of Barakat and civilians.
The force of Monday's car bomb blast destroyed the facades of nearby apartment buildings, witnesses said. One man said the powerful explosion blew debris everywhere.
Amateur video showed firefighters trying to douse flames from burning vehicles after a powerful car bomb blast struck the convoy. Initial reports said Barakat was "lightly wounded," but the state news agency later said he died during "critical" surgery.
A little-known group calling itself the "Giza Popular Resistance" claimed responsibility for the attack on its Facebook page, posting pictures that it said were from the explosion. The claim could not be independently verified.
Militants in Egypt have previously focused most of their attacks on the police and military, but in recent months have been increasingly targeting members of the judiciary.
A statement from the office of President Abdel Fattah el-Sissi called the attack "heinous" and said Egypt had lost a model of judicial integrity. It said the government was canceling celebrations planned for Tuesday marking the second anniversary of the mass protests that led to the ouster of Morsi.
The United States also strongly condemned the terrorist attack. A State Department spokesman, John Kirby, said the United States "stands firmly with the Egyptian government in its efforts to confront terrorism."
U.N. Secretary General Ban Ki-moon called for those responsible for the attack to be brought to justice.
The attack on Barakat was the most high-profile in Egypt since the attempted 2013 assassination of Interior Minister Mohammed Ibrahim.
Since Morsi was forced from office, his Muslim Brotherhood has been the subject of a crackdown including thousands of Islamists being arrested and charged, with many convicted in mass trials. Morsi is among the Brotherhood leaders who have been convicted and given death sentences.
Cairo Governor Galal Mustapha Saeed told Egyptian media that he visited the blast site and that security measures were in place for Tuesday, the second anniversary of Morsi's removal.
Government spokesman Hossam Koweitch told Egyptian TV that Prime Minister Ibrahim Mehleb was cutting short a visit to Upper Egypt and returning to Cairo. He insisted the attack was aimed at creating turmoil in Egyptian society.
The Arab League also met in Cairo Monday to discuss recent acts of terrorism in a number of Arab states, including Tunisia, Kuwait and Egypt. Arab League head Nabil Elarabi declared that the body stood by member states hit by acts of terrorism. He likewise said recent attacks aimed to destroy the underpinnings of Arab society.