Two people were killed and nine wounded, including seven policemen, in a bomb explosion outside the Egyptian supreme court in Cairo, the health ministry said.
Ministry spokesman Hossam Abdel Ghaffar told AFP that a 22-year-old man "died of injuries sustained in his backbone" in the attack.
Another man, aged 24, who had suffered head injuries and internal bleeding, also died of his wounds, he said.
Hospital officials earlier said that a man was in critical condition as the blast blew away part of his skull and brain.
Abdel Ghaffar said nine people, including seven policemen, were wounded in the attack.
The explosion appeared to be aimed at a police checkpoint near the court, a hospital official said.
Two other minor bombs were set off in Cairo several hours later Monday, one outside a fire station and another in front of a police station, but there were no casualties, the Interior Ministry said on its Facebook page.
The latest attacks came a day after two civilians died in a bombing outside a police station in southern Egypt.
A worker in a nearby cafe said he ran out into the street after hearing a loud explosion.
"I found three people lying on the ground covered in blood."
Police sealed off the area and swept it with sniffer dogs as ambulances tried to reach the site through a crowd of onlookers.
- Focused on security forces -
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Militants have regularly set off bombs in the capital, mostly targeting police, since the 2013 military overthrow of Islamist president Mohamed Morsi unleashed a deadly crackdown on his supporters.
It was the second such attack near the court after an explosion wounded 12 people in October last year.
Monday's explosion came days after a series of bombings in Cairo in which one person was killed.
Five bombs struck within hours, four of them near mobile phone service companies and a police station.
Most of the bombings in the capital have been rudimentary and caused no casualties.
But several have killed policemen, including two senior officers who died while trying to defuse bombs outside the presidential palace in June last year.
Those bombs and several others that killed policemen in Cairo were claimed by the Ajnad Misr (Soldiers of Egypt) jihadist group.
The deadliest attacks since Morsi's overthrow have been launched by the Islamic State group's affiliate in Egypt, Sinai-based Ansar Beit al-Maqdis, which has killed scores of soldiers and policemen.
The organisation set up branches in the Nile Delta, targeting police headquarters in Cairo and other cities before a police crackdown last year.
Jihadists, who have focused their attacks on security forces, are also believed to be planning attacks on embassies of countries that have backed the former army chief and now President Abdel Fattah al-Sisi, according to officials.
Sisi was elected to office in May 2014 pledging to eradicate the militants, but he has had limited success, especially against the Sinai insurgency.
On January 29, simultaneous car bombings and mortar attacks on security headquarters in the peninsula killed at least 30 people, most of them soldiers.