Four Nigerian men have received 20 lashes each after an Islamic court in the northern city of Bauchi convicted them of gay sex, officials say.

Confessions had been forced from the Muslim men after they were beaten up in custody, a rights activist said.

They were among a group of people arrested late last year.

Homosexual acts are illegal in the West African state under both Islamic and secular law - the latter was tightened earlier this year.

Same-sex marriages, gay groups and shows of same-sex public affection are now banned throughout Nigeria.

'Ordered to pay fine'

Another Muslim man also received 20 lashes in January after the Islamic court in Bauchi convicted him of homosexual offences.

Most states in the predominantly Muslim north of Nigeria have adopted Islamic law, known as Sharia, since the end of military rule in 1999.

The BBC's Ishaq Khalid in Bauchi says details about the latest case are sketchy, but court officials have confirmed the whippings.

It seems the court wanted to avoid publicity after an angry crowd disrupted proceedings last month, demanding the death sentence for the four, our reporter says.

The judge did not impose the death penalty because the homosexual offences had taken place a long time ago, and the men had repented, he says

The men, aged between 20 and 22, were also ordered to pay a fine of $120 (£70) each, Dorothy Aken'Ova, a rights activist with the Nigeria-based International Centre for Reproductive Health and Sexual Rights, told the Associated Press news agency.

Rights groups were trying to raise the money - otherwise, they will remain in prison, she said.

The men should not have been convicted because they were beaten up and their confessions forced, she said.

Their families, mainly subsistence farmers, turned down an offer of legal representation because they preferred to negotiate with the judge and get the case behind them, Ms Aken'Ova said.

Nigeria is a deeply conservative country, where most people - Christian and Muslim - are opposed to homosexuality.