By Ahmed Hassan and Omar Fahmy
CAIRO, June 29 (Reuters) - Egypt's top public prosecutor died of wounds sustained in a car bomb attack on his convoy as it was leaving his home on Monday, the most senior state official killed in militant violence since the toppling of an Islamist president two years ago.
Judges and other senior officials have increasingly been targeted by radical Islamists opposed to President Abdel Fattah al-Sisi and angered by hefty prison sentences imposed on members of the now-outlawed Muslim Brotherhood.
Last month, the Islamic State militant group's Egypt affiliate urged followers to attack judges, opening a new front in an Islamist insurgency in Egypt..
Chief prosecutor Hisham Barakat was the highest-ranking state official to die in a militant attack since Sisi, a former army chief, ousted Islamist president Mohamed Mursi in mid-2013 after mass protests against his rule.
Mursi, a Brotherhood leader who was freely elected as Egypt's president in 2012, was sentenced this month to death over a mass jailbreak in 2011. The Brotherhood has denied any link to recent militant bloodshed, reiterating what it calls a long commitment to non-violence.
Monday's attack stirred fears of yet more turmoil in Egypt, which has been struggling since the 2011 popular uprising that toppled Hosni Mubarak to regain full-fledged stability and revive the economy of the Arab world's most populous country.
The bombing, which left cars ablaze and store fronts damaged, also showed the risk of militant Islam threatening the Egyptian state leadership as it did in the 1980s and 1990s.
State media confirmed the death of Barakat, 64, at a hospital in the residential district of Heliopolis where he had undergone surgery hours earlier, and said he would receive a military funeral.
Health Minister Adel Adawi told reporters outside al-Nozha hospital where Barakat was admitted that the cause of death was "ruptures in the lung and stomach, and internal bleeding."
There was no confirmed claim of responsibility for the attack, in which security sources said a bomb in a parked car was remotely detonated as Barakat's motorcade left his home. They initially said a car bomber had rammed into the convoy.
The state news agency MENA said the bomb blast also wounded at least nine other people including police and civilians. The explosion sent a large plume of black smoke aloft in front of a row of apartment buildings near the military academy.
Sisi's office declared Tuesday an official holiday to mourn Barakat's death, canceling celebrations prepared to mark the anniversary of mass unrest that led to Mursi's fall, and said the perpetrators would draw "the most severe punishment."
"These kinds of vicious attacks will not deter the state from continuing its path of development, the adoption of rights, and realizing the hopes and aspirations of the Egyptian people," it said in a statement.
The Egyptian judiciary says it is independent of the government and military. But some of Egypt's judges have drawn accusations of blatant bias by handing down lengthy jail terms and mass death sentences against Islamists.
"Terrorism killed the top man of our prosecution but despite this we will not be scared and we will continue our work," said Judge Ashraf Abdelhady as he left the hospital.
A presidential spokesman told MENA that the interior ministry would increase security measures ahead of the June 30 anniversary, including heightening the alert level and reinforcing security at vital installations.
Barakat's place of work was also targeted earlier this year when a bomb exploded near the High Court in central Cairo, killing two people.
Egypt is grappling with a Sinai-based insurgency that has killed hundreds of policemen and soldiers since Mursi's fall. The most active group is Sinai Province, which has pledged allegiance to Islamic State, the ultra-hardline jihadist group that has seized control of significant areas of Iraq and Syria.
At least two people were killed and 12 wounded in a blast later on Monday likely caused by a roadside bomb near Sheik Zuweid in North Sinai, security sources said.
Last month, suspected Islamist gunmen killed three judges in the Sinai city of al-Arish. (Additional reporting by Stephen Kalin, Ahmed Aboulenein, Shadi Bushra and Lilian Wagdy; Writing by Yara Bayoumy; Editing by Mark Heinrich)