New legislation, signed into law by the president without announcement, bans same-sex marriages, gay groups and shows of same-sex public affection.
It is already illegal to have gay sex in Nigeria - now same-sex couples could face up to 14 years in prison.
The new law recommends prison sentences of up to 10 years for anyone who participates in gay clubs or organisations and for same-sex couples who publicly show affection.
"Any person who registers, operates or participates in gay clubs, societies and organisations or directly or indirectly makes public show of same-sex amorous relationship in Nigeria commits an offence and shall each be liable on conviction to a term of 10 years in prison," the Same-Sex Marriage Prohibition Act says.
The act, which was adopted by the Senate in 2011 and passed by the lower house of parliament last May, was signed by President Goodluck Jonathan earlier this month.
"This is a law that is in line with the people's cultural and religious inclination. So it is a law that is a reflection of the beliefs and orientation of Nigerian people," presidential spokesman Reuben Abati told the Associated Press news agency.
According to AP, the few Nigerian gay and human rights activists who tried to give evidence last year during the parliamentary debate were heckled and booed until one broke into tears and another could not be heard.
http://www.bbc.co.uk/news/world-africa-25728845
An Islamic court in Nigeria's northern state of Bauchi has put on trial 11 Muslim men accused of being homosexuals in violation of their religion, a religious leader has told the BBC.
A 12th person arrested - a Christian - would be tried under secular law, a BBC reporter says.
Under Islamic law, a person can be sentenced to death by stoning if convicted of homosexuality.
It is also illegal to have gay sex in Nigeria, according to its secular laws.
Earlier this month, President Goodluck Jonathan signed a parliamentary bill which tightens laws against homosexuals, banning same-sex marriages, gay groups and shows of same-sex public affection.
The new legislation applies across Nigeria, affecting all citizens.
Most states in the predominantly Muslim north of Nigeria have adopted Islamic law, known as Sharia, since the end of military rule in 1999.
Nigeria is a deeply conservative country, with an influential Christian evangelical movement in the south and strong support for Islamic law among many Muslims in the north.
http://www.bbc.co.uk/news/world-africa-25749308
See also
http://www.washingtonpost.com/world/africa/nigerian-leader-signs-law-banning-marriage/2014/01/13/83263b0c-7c71-11e3-97d3-b9925ce2c57b_story.html
Nigeria has decided to cross a line, with Muslims and Christians joining together to persecute homosexuals. This is such a blatant violation of human rights, and go so far (even non-homosexuals may be punished for supporting homosexuals) that in my opinion the international community must react in a strong and decisive manner. That includes condemnation, international pressure, and cutting off aid. This is totally unacceptable.
"Rarely have I seen a piece of legislation that in so few paragraphs directly violates so many basic, universal human rights"
- Navi Pillay
Do you agree, or do you think the international community should stay out of what is largely a domestic affair?