At least 78 people have been killed in an explosion at a petrol station in the Ghanaian capital Accra, the fire service told local media.

People taking refuge in the station during a heavy downpour were killed in the explosion, local media reports.

The fire department in still removing bodies from the petrol station near Mkrumah Circle, Citi FM reported.

About a dozen people were taken to hospital after the blast, which is believed to have been an accident linked to the downpour, Prince Billy Anaglate said, reports Reuters.

The floods have cut power supplies across much of the city, and left many homeless.

"Many suburbs of Accra and surrounding parts have been heavily affected leading to heavy restriction of movement of people," the Ministry of Communications said in a statement. "The general public is kindly advised to avoid fast moving rainwater, and areas they know have big drains. Stay on higher ground, where necessary, to prevent loss of life."