Kampala - Ugandan police broke up a gay pride event in the capital and arrested about 20 people, a gay rights leader said on Friday.This was the latest incident highlighting the risks homosexuals face in Africa.A fashion show was underway at a nightclub in Kampala when police showed up and asked who the organisers were, said Frank Mugisha, who was immediately handcuffed when he identified himself to a police commander as a leader among those attending the event.About 20 others were arrested, put on a police truck and driven to a police station for questioning, he said.Mugisha said they were released more than two hours later without being charged, although some who had been detained said they had been slapped or pushed around by officers. One man trying to escape arrest at the nightclub had injured himself while jumping to safety, he said."We condemn the police's actions, the use of excessive force during arrest," he said.Patrick Onyango, a spokesperson for Ugandan police, confirmed the arrests but gave no details.Homosexuality is illegal in Uganda under a colonial-era law that prohibits sex acts "against the order of nature."This incident highlights the challenges faced by gays in Uganda, where many people despise homosexuality and believe it is imported from the West. In 2009 a Ugandan lawmaker introduced a bill that prescribed the death penalty for some homosexual acts, saying he wanted to protect Ugandan children. The proposed bill prompted international condemnation and eventually, a less severe version passed by lawmakers was rejected by a court as unconstitutional.Watchdog groups say LGBTI Ugandans routinely face violence, discrimination and extortion."Tonight's outrageous and unlawful government raid on a spirited celebration displays the extreme impunity under which Ugandan police are operating," Health GAP, a US-based Aids advocacy group, said in a statement. "We call on governments and UN bodies to immediately and publicly condemn this brutal raid and call on government to take swift disciplinary action against those responsible for these gross violations of rights and freedoms."