CAIRO (AP) -- Egypt's state media say attackers have hurled a grenade at a police checkpoint north of Cairo, wounding two policemen and two civilians.
The state MENA news agency says the attackers were riding on a motorbike Friday when they threw the grenade on a bridge in the Qalioubiya province.
Attacks against security forces in Egypt have increased since troops violently dispersed two Islamist sit-ins in August in Cairo. The police crackdown set off a day of violence across the country that killed hundreds.
The sit-ins were protesting the ouster of President Mohammed Morsi in a popularly-backed coup.
Attacks against Egyptian forces have mostly been taking place in the volatile Sinai Peninsula where the army says it's waging a war against militants, but some have also taken place in Cairo.