CAIRO — Security officials said an explosion has hit a public bus in the Egyptian capital Cairo, wounding five people.

There were also unconfirmed reports of one death, according to Egyptian news site al-Ahram.

The officials said the blast went off Thursday morning as the bus passed through Cairo’s eastern Nasr City district. They said the cause was still uncertain but they suspected an explosive device was thrown at the bus or set nearby.

The officials spoke on condition of anonymity because they were not authorized to talk to the press.

Egypt has seen a wave of attacks blamed on Islamic militants since the July military ouster of Islamist President Mohammed Morsi and the subsequent crackdown on his Muslim Brotherhood group.

On Tuesday, a suicide car bomber struck a police headquarters in the Nile Delta city of Mansoura, killing 15 people, in the worst bombing yet.

In September Egypt’s Interior Minister Mohammed Ibrahim was apparently targeted by a “large” explosive device that was likely detonated by remote control as he drove through the Nasr City district.

Security officials said six passers-by were injured in the attack, but that there were no fatalities. The blast damaged several cars parked on the street and shattered the windows of several nearby apartment buildings.

The Interior Minister is in charge of the country’s police force.

Nasr City is a stronghold of the Muslim Brotherhood, the Islamist group from which ousted President Mohammed Morsi hails. It was also the site of a sit-in protest by his supporters that was stormed by police on Aug. 14, killing hundreds.

Morsi was toppled in a July 3 military coup that followed days of protests by millions of Egyptians who demanded his departure after a year in office. During the six-weeklong sit-in protest in Nasr City, many of Morsi’s supporters threatened to wage a campaign of violence against the military-backed government if he was not reinstated.

Times of Israel staff contributed to this report.