Government and hospital officials in the Republic of Congo say a series of explosions at a weapons depot in the capital, Brazzaville, has killed about 200 people and injured about 200 more.

Authorities say the arms facility, located on the banks of the Congo River, caught fire early Sunday causing the powerful blasts.

The explosions flattened roofs and sent dark, black smoke into the sky and panicked residents into the streets.

Emergency crews rushed the injured to crowded hospitals, where relatives had gathered to search for missing loved ones.

It was not immediately clear what started the fire, but officials say it did not appear to have been intentionally set.

A Chinese consulate official in Brazzaville told Beijing's Xinhua news agency that at least four Chinese workers were among those killed and that dozens of others were injured. Duan Jinzhu is quoted as saying the embassy was trying to obtain more information about the casualties.

The state news agency reported the workers belonged to the Beijing Construction Engineering Group in the Republic of Congo.

The explosions also rattled Kinshasa, the capital of the Democratic Republic of Congo across the Congo River.