Gunmen shot dead a Nigerian soldier in an ambush in the southern oil hub of Port Harcourt on Saturday, the military said, as voters were casting their ballots across the country in a presidential election, Reuters reported. Brigadier-General K.A. Essien told reporters in Port Harcourt, the centre of Africa's biggest oil and gas industry, of the attack but gave no further details. -- SPA 18:46 LOCAL TIME 15:46 GMT تغريد