At least 150 people are reported to have been killed in huge explosions at an arms dump in Brazzaville, the capital of Congo.
Hundreds more people are reported to have been injured.
Troops and police have sealed off the area.
The force of the blasts was felt several miles away in the city of Kinshasa, across the border in the Democratic Republic of Congo.
A BBC correspondent says the explosions started on Sunday morning and continued into the early afternoon.
Xinhua news agency said one Chinese worker had been killed and several others injured.
It said about 140 Chinese workers from a Beijing construction company were in the area when the explosions took place.