CAIRO -- An explosion rocked a chemicals factory near Cairo's airport Thursday night, prompting firefighters and ambulances to rush to the scene.

The reason for the blast Thursday night was not immediately known.

A military spokesman, Col. Tamer al-Rifai, said on Facebook that the explosion occurred in a petrochemical warehouse of the Heliopolis chemical company.

People in Egypt's capital residents reporting hearing a loud explosion and then seeing red smoke rising from the factory.