The explosion of a suspected homemade bomb targeting a tram station in eastern Cairo wounded at least one person on Saturday, Egyptian security officials said.
Since the military ousted Islamist president Mohamed Morsi in July, militants have stepped up attacks against the security forces in Egypt, killing many soldiers and policemen.
However, attacks on civilian targets have been rare.
Another homemade bomb was defused at the same station, the security officials said.
Signup to our newsletter and follow us on Facebook and Twitter!
In February, a bomb that struck a bus carrying tourists near the Taba border crossing in South Sinai killed three people, including three South Koreans.
The Al-Qaeda-inspired Ansar Beit al-Maqdis claimed the attack.
It has also claimed responsibility for high-profile attacks including a car bombing at a police headquarters in Cairo and the shooting down of a military helicopter in the Sinai Peninsula.
The Sinai-based group said the attacks were in revenge for a deadly crackdown by the security forces on Morsi supporters.
More than 1,4000 people have been killed in the crackdown, according to Amnesty International. Thousands have also been jailed.