(CNN) -- — Five people were wounded Thursday in an explosion near Al-Azhar University in Cairo's Nasr City neighborhood, according to local media reports.
A bomb disposal team defused a second bomb, al-Masriya state TV reported.
The Nasr City neighborhood is a traditional stronghold of supporters of deposed Egyptian President Mohamed Morsy of the Muslim Brotherhood.
Egypt's interim government officially has declared the Muslim Brotherhood a terrorist organization, blaming it for a recent bombing despite the fact a different organization claimed responsibility for the attack.
The United States objected to the government's assault on the Muslim Brotherhood's reputation.
Thursday's blast comes in the lead-up to Egypt's referendum on a new constitution, which will be held January 14-15.
If passed, the constitution would ban religious parties and put more power in the hands of the military.