Sudanese officials say eight children have been killed in an explosion near a military facility where they were searching for scrap metal to resell.

The officials say the explosion happened Saturday in Omdurman, the twin city of the capital, Khartoum. They spoke on condition of anonymity because they were not authorized to brief reporters.

The Central Committee of Sudan Doctors, an independent professional union, says seven children died at the scene and the eighth succumbed to wounds in a hospital.

The committee is part of an umbrella opposition movement that has been organizing street protests since December calling on President Omar al-Bashir to resign. A security crackdown has killed dozens of people.