At least 90 people were killed in a fire at a petrol station in Ghana's capital, Accra, as they sought shelter from heavy rains that caused widespread flooding, emergency services said yesterday.

The fire broke out at the filling station in the Kwame Nkrumah Circle area of the city late on Wednesday night and is thought to have spread from a nearby residence.

The explosion was heard and seen across the capital.

Ghana's President John Dramani Mahama described the loss of life as "catastrophic and almost unprecedented", as he toured the scene of the disaster on Thursday morning.

"A lot of people have lost their lives and I am lost for words," he told reporters.

"As at now, the confirmed figure is hovering around 90 but I know it will be more than that," national police spokesman Arthur Cephas told AFP.

Rescue officials were working to clear the area and bodies were piled onto flat-bed trucks, covered with tarpaulin sheets, as police in high-visibility vests stood guard at the scene.

Local hospitals said morgues were full and security officials said the death toll was likely to rise, as fire investigators picked through the charred debris to determine what caused the inferno.

Dozens of motorcycles were seen burnt and the fire is also thought to have engulfed a bus full of passengers that was waiting on the forecourt, an AFP reporter at the scene said.

Local residents said many people had sought refuge under the filling station canopy from days of heavy rains that have engulfed Accra. It was not immediately clear exactly how the victims died, with reports that some had drowned after being knocked unconscious and falling into the flood waters.

At least two days of rains have caused chaos in Accra, leaving many suburbs submerged and people stranded, as roads were blocked and cars were carried away in or upturned by the flood waters.