Twelve young men were arrested in the north Nigerian city of Kano for allegedly planning a gay wedding, the Islamic law-enforcement agency, the Hisbah, said on Tuesday.
The suspects, most of them teenagers, were detained on Monday at a popular resort on the outskirts of the city, said the head of the Hisbah, Aminu Daurawa.
Homosexuality is banned under federal law in Nigeria, where last year new legislation was passed outlawing same-sex marriages and the promotion of civil unions.
In northern states, where Sharia runs parallel to the state and federal justice system, homosexuality is punishable by death, although the sentence is rarely, if ever, enforced.
"We have 12 men in custody, including the bride. We arrested them at the venue of a planned gay wedding," Daurawa told AFP.
"We got information of the wedding four days earlier and our men stormed the venue while the wedding was about to start."
Many guests escaped during the raid, he added.
But one of the participants, 18-year-old Faruk Maiduguri, told reporters at the Hisbah offices that he and his friends were only celebrating his birthday.
"It was my birthday party, not a gay wedding," he said in tears.
Daurawa said the suspects, who came from Kano, the northern cities of Maiduguri, Kaduna and Bauchi, and Ibadan and Osogbo in the southwest, "looked and acted feminine", which prompted their arrest.
It was not clear whether they would be charged but their families had been summoned, he added.
In January last year, more than a dozen men suspected of organising a gay wedding were arrested and charged in Bauchi by the Sharia agency.
Some of them were discharged while others were released on bail.
Nigeria's Same Sex Marriage (Prohibition) Act carries penalties of up to 14 years in jail for anyone confirmed to be in a gay union.
The government said the legislation reflected public opinion in religiously conversative Nigeria, which is split almost evenly between a mainly Muslim north and predominantly Christian south.
But gay rights activists in Nigeria and abroad, the United Nations and Western countries, including the United States, attacked the law as a breach of human rights.