Islamist militant group Boko Haram has released photos apparently showing a rocket-making factory in north-eastern Nigeria.
The group has used rocket-propelled grenades in the past and many Nigerians have been asking where the weapons have been coming from.
The photos seem to indicate that members of the group have the technical know-how to manufacture weapons.
The pictures are believed to have been taken in a college in Borno state.
Analysts say it looks as though the machinery is from Bama, a town in north-eastern Nigeria recently recaptured from Boko Haram.