Accra - A tanker delivering natural gas caught fire in Ghana's capital Accra on Saturday, triggering two explosions that were heard across the city causing fires that forced local residents to flee.Police said the blasts happened in the Atomic Junction roundabout area of Legon in northeast Accra at about 1930 GMT."I am in Legon and I heard two explosions. My whole building was shaking," spokesperson Efia Tenge told AFP.Ghana National Fire Service spokesperson Billy Anaglate said the tanker fire caused explosions at a liquefied natural gas station and at a nearby petrol station."It's too early for us to know the cause of the fire. We will investigate. There are some vehicles that were also burned as a result of the explosions," he told AFP.An AFP correspondent said the area had been cordoned off. Fire crews and ambulances were at the scene. But Anaglate said he had no immediate information on casualties.The Accra city authorities warned people to avoid the area, which is also home to the University of Ghana campus.The blasts will likely revive memories of June 2015 when more than 150 people were killed as they sought shelter from seasonal rains and flooding at a petrol station.Leaked fuel floating on top of rising waters had caught fire, burning down buildings and the filling station, trapping people in vehicles as the pumps exploded.Accra has been pounded by heavy rains in recent days, causing many roads to flood. Two years ago, open drains blocked with litter were blamed for the flooding.Saturday's blasts were heard across the city and sent a huge fireball into the night sky.Kobby Boateng, a computer programmer, said he had returned to the university campus with his girlfriend when the blast happened."All of a sudden, we heard a 'boom' and the flash of an explosion, which made the building just shake and the lights went out," he said."People were rushing out of their rooms. Some of them were naked and the heat that was coming from that blast, my God, it was unbearable."