Lagos , Nigeria ( CNN ) -- Nigerian authorities arrested 10 people believed to be gay men under a bill signed this week that bans same-sex marriages , a human rights group said . Police detained men in various states and have dozens of pending arrests based on perceived sexual orientation , according to Amnesty International . `` Those arrested under this draconian new legislation must be released immediately and the charges against them dropped . Locking someone up for their sexual orientation violates the most basic human rights standards , '' Makmid Kamara , a researcher for the rights group , said in a statement Wednesday . Nigerian police spokesman Frank Mba angrily suggested no one had been arrested due to the new law . `` I challenge Amnesty International to publish details of persons alleged to have been arrested in connection with the new anti-gay law , stating clearly when they were arrested , where they were arrested , the police station or department that carried out the arrest , etc. , '' Mba told CNN Thursday . `` The new anti-gay law is primarily designed to prevent same sex marriages and unions in Nigeria . So far , ( to the best of our knowledge ) no Nigerian has come out to declare his intention of engaging in such an illicit union . Therefore , the question that naturally arises is : how can the police arrest 'suspects or offenders ' not known to them or to the law ? '' In Bauchi state , Amnesty said an assistant commissioner of police confirmed that authorities had placed `` a list of suspected gay people '' under surveillance . The group said police arrested the men in Anambra , Enugu , Imo and Oyo states . `` Reports that the police in one state are apparently drawing up lists of members of the lesbian , gay , bisexual , transgender and intersex community to target are extremely worrying , '' Kamara added . Mba took issue with that claim as well . `` Who is this assistant commissioner of police ? Amnesty International should provide his name and designation . Without providing details of the sources of their stories , third parties like CNN can not independently verify the authenticity or accuracy of such stories . The anonymity of the story raises a big credibility question . `` Bauchi State Police Command alone has a total of seven assistant commissioners of police . There are hundreds of ACPs nationwide . Thus , without properly identifying the ACP in question , I will treat the story as mere fiction . '' President Goodluck Jonathan signed the bill Monday after parliament passed it last year , despite international pressure against it . It bans same-sex marriages and civil unions , and includes sentences of up to 14 years in prison for gay couples . The bill also forbids the operation of gay clubs , societies or meetings in Nigeria . The punishment for such acts is 10 years in prison . U.S. Secretary of State John Kerry joined the United Nations in condemning the bill . `` This law dangerously restricts freedom of assembly , association and expression for all Nigerians , '' Kerry said . `` People everywhere deserve to live in freedom and equality . No one should face violence or discrimination for who they are or who they love . '' U.N. chief Ban Ki-moon expressed concerns , saying he was alarmed by reports of arrests and torture . He said he fears the bill will lead to violence and discrimination . . Last month , the Ugandan parliament passed controversial legislation that would make some gay acts punishable by life in prison . President Yoweri Museveni has not signed it yet . Homosexuality is illegal in most African nations based on remnants of sodomy laws introduced during the British colonial era . The laws are perpetuated by cultural and religious beliefs . Punishments across the continent range from fines to years in prison . Last year , a Pew Research Center report found African and Muslim nations are the least accepting of homosexuality . Of the 39 countries surveyed , Nigeria was the most intolerant . At least 98 % of respondents in the nation said homosexuality is unacceptable . CNN 's Vladimir Duthiers reported from Lagos , and Faith Karimi from Atlanta . CNN 's Nana Karikari-apau contributed to this report .
NEW : Police spokesman denies arrests , denounces Amnesty report as fiction . Police also compile a list of people for surveillance . At least 98 % of respondents in the nation say homosexuality is unacceptable . Homosexuality is illegal in most African nations .