A Rwandan priest accused of helping to orchestrate the 1994 genocide in his native country has been held in Uganda, police say.
Jean-Bosco Uwinkindi was arrested after entering western Uganda from the Democratic Republic of Congo.
Mr Uwinkindi was indicted in 2001 by a UN-backed tribunal for genocide and crimes against humanity.
About 800,000 Tutsis and moderate Hutus were killed by Hutu militias in the 100-day slaughter in 1994.
Mr Uwinkindi was taken into custody on Wednesday, Ugandan police announced on Friday.
Police said the suspect had been tracked for two days before being detained.
Mr Uwinkindi entered Uganda under a different name and was trying to buy land and settle in the country, Uganda's Daily Monitor newspaper reports.
The indictment by the International Criminal Tribunal for Rwanda (ICTR) says that Mr Uwinkindi was a pastor at a Pentecostal Church near Rwanda's capital, Kigali, in 1994.
He is accused of ordering the killing of Tutsis, including women and children, after they had sought refuge in his church.
The prosecution alleges that in investigations after the genocide, some 2,000 corpses were found near the church.
Until his arrest, Mr Uwinkindi was one of the ICTR's 11 most wanted suspects.
The US had offered a $5m (£3.3m) reward for information leading to his arrest. It is still not clear whether anyone will claim that reward.
Elly Womanya, deputy director of Interpol's Kampala office, told the AFP news agency that the suspect would be transferred to the ICTR in Arusha, Tanzania, as soon as possible.
Mr Uwinkindi is the second Rwandan genocide suspect to be arrested in Uganda in less than a year. In October 2009, Idelphonse Nizeyimana, the former Hutu intelligence chief, was seized in Kampala.