Homosexual acts are already illegal in Nigeria. But for its lawmakers that does not appear to be categorical enough.

The Prohibition of Same-Sex Marriage Bill last week sailed unopposed through the Senate - the country's highest chamber.

Under the new bill, same-sex couples entering into either marriage or cohabitation would face jail terms of up to 14 years.

Amnesty International said the move threatens the basic human rights of a large number of Nigerians.

Jonah Fisher reports from Abuja.