Nigeria's President Muhammadu Buhari has unveiled a new visa policy which he says is intended to attract innovation, specialised skills and knowledge from abroad.The president had last November in Egypt, announced the new visa policy which he described as a "strategic decision to bring down barriers that have hindered the free movement of our people within the continent".The new policy sees the introduction of visas on arrival for short visits for holders of passports of African Union countries.There are 79 new categories which the government say is to ensure that "visas are more efficiently matched to the purpose of travel, thus helping improve the efficiency of processing and response".The government also announced a new biometric visa database which is able to conduct checks for those on Interpol watchlists.