COPENHAGEN, Denmark — Police in Norway say they have arrested a man suspected of participating in the murder of mainly Tutsis in the 1994 genocide in his African homeland.

The National Criminal Investigation Service says the man in his 50s was arrested Tuesday. His name was not disclosed.

The NCIS said Thursday the man arrived in Norway in 2006 as a refugee and became a Norwegian citizen in 2014.

Prosecutor Espen Hanken said there is still a lot of investigation ahead, adding the case has been built on information from Rwanda and "investigative trips" to the African country. The aim, he said, is to have it prosecuted in Norway.

Some 800,000 people, mostly ethnic Tutsis, were killed by Hutu extremists during the Rwandan genocide, according to the U.N.