At least eight people were killed and 84 injured after a blast at an oil terminal in Guinea's capital, Conakry, early on Monday, a senior police officer said, adding that the blaze was being contained.

The explosion at the West African nation's main oil terminal rocked the Kaloum administrative district in downtown Conakry, blowing out the windows of several nearby homes and forcing hundreds to flee, according to a Reuters witness.

A huge fire and billowing black smoke were seen from miles away as firefighters rushed to the area, while several tanker trucks left the depot, escorted by soldiers and police.

Guinea is not an oil producer and has no oil refining capacity. It imports refined products, which are mostly stored in the Kaloum terminal and distributed via trucks across the country. The extent of the damage to the terminal is unclear for now.

The country has a small oil depot at the port in Kamsar, north of Conakry, which is mostly used by mining firms.

Later on Monday, a thick column of smoke and some flames were still visible after firefighters brought the fire under control.

The origin of the fire was unknown, the government said in a statement, adding that an investigation will be launched to establish the cause and determine who might be responsible.

"The Government expresses its deep concern about this event, the scale and consequences of which could have a direct impact on the population," the statement said.

It urged people to stay at home and said the schools will be closed on Monday.