East Africa’s richest man, said to be Africa’s youngest billionaire, Mohammed Dewji, 43, has been kidnapped in Dar es Salaam, police say.

Mr Dewji, who is a fitness enthusiast, was kidnapped by four masked men outside a swanky hotel gym in an affluent neighbourhood of Tanzania's commercial capital, where he was going for his routine morning workout.

According to Dar es Salaam Regional Commissioner Paul Makonda, two of the attackers are believed to be foreign nationals.

He also said three people have been arrested in connection with the incident.

Authorities are yet to establish the motive for the kidnapping and where they are keeping the businessman.

Environment Minister January Makamba, a friend of Mr Dewji, tweeted that he had spoken to Mr Dewji’s father and the family confirmed that he had been kidnapped.

Mr Dewji, locally known as Mo, is credited with turning his family business from a wholesale and retail enterprise into a multi-billion dollar pan-African conglomerate.

Forbes estimates that he is worth $1.5bn (£980m).