Twelve people have been injured after an explosion at a chemical factory near Cairo's airport, Egypt's state news agency MENA says.
They have been hospitalised, but the severity of their injuries is not yet known.
An army spokesman said the blast was caused by "high temperatures" at a fuel storage facility.
Air traffic at the airport has not been affected, Egypt's aviation minister Younis al-Masri confirmed.
According to eyewitnesses, the sound of the explosion was deafening and flames could be seen from a distance.
Pictures shared on social media appear to show a fireball rising into the air in the Heliopolis district.
Firefighters have since managed to subdue the flames, according to state television.