A series of powerful blasts shook Brazzaville, the capital of the Republic of Congo, early Sunday, sparking panic in the city and also in neighboring Kinshasa across the Congo River.

Diplomats and government officials say the explosions took place at a weapons depot along the Congo River in the northern part of Brazzaville. Witnesses reported hearing at least three blasts.

It was not immediately clear what caused the explosions or how many casualties resulted.

A Chinese consulate official in Brazzaville told Beijing's Xinhua news agency that one Chinese worker was killed and several were injured.

The official said the workers belonged to the Beijing Construction Engineering Group in the Republic of Congo.

Witnesses said the blasts sent large plumes of smoke into the air, and also blew out windows across the river in Kinshasa, capital of the Democratic Republic of Congo.