Twenty people have been arrested on Tanzania's semi-autonomous archipelago of Zanzibar for alleged homosexuality, police say.
The 12 women and eight men were picked up in a hotel where they were receiving training about HIV/Aids education programmes.
Earlier this year, authorities banned many private health clinics from providing HIV/Aids services, saying they encouraged gay sex.
Homosexuality is a crime in Tanzania.
Regional police commander Hassan Ali Nasri said on state television: "They are implicated in homosexuality. We arrested them and are busy interrogating them. The police cannot turn a blind eye to this practice."
On Friday, Deputy Health Minister Hamisi Kingwangalla vowed in front of parliament to "fight with all our strength against groups supporting homosexuality in our country," AFP news agency reports.
In July 2016, the government banned the import and sales of sexual lubricants, with Health Minister Ummy Mwalimu saying it encouraged homosexuality which led to the spread of HIV/Aids, AFP adds.
Gay male sex is punishable by up to 30 years in jail in the country.
Despite the ban on homosexuality, Tanzania was until recently somewhat more tolerant towards gay people than many other African countries, but a rise in anti-gay rhetoric by the government has led to a spike in discrimination, correspondents say.
In July, human rights group Amnesty International said the authorities were "arresting and prosecuting people on homosexuality-related charges, and subjecting them to forced anal examinations".