Assailants threw a grenade and raked a police car with gunfire in a drive-by attack on an Egyptian traffic police checkpoint in Cairo on Tuesday, wounding one person, security sources said.
Bombings and shootings targeting the security forces have become commonplace since the army deposed Islamist President Mohamed Morsi in July following mass protests against his rule.
While the attacks have mostly hit the army and police in the lawless Sinai Peninsula, they have spread to the more heavily populated Nile Delta and Valley.
Tuesday's attack occurred on a usually busy flyover running through the heart of Cairo. Security sources initially said it happened near the upscale district of Zamalek, but later said it took place in the nearby Mohandeseen district.
It was at least the fourth in Cairo or areas north of the capital since Dec. 24, the day a suicide car bomber killed 16 people at a police station in the Nile Delta city of Mansoura.
The Sinai-based, Islamist militant Ansar Bayt al-Maqdis group claimed responsibility for the Mansoura bombing. The military-backed government blamed Morsi's Muslim Brotherhood, which condemned the attack. Ansar Bayt al-Maqdis has also claimed other attacks on the police and army.