Vincent Bajinya, Charles Munyaneza and Celestin Ugirashebuja were arrested Thursday and were remanded in custody by the City of Westminster Magistrates Court in London Friday, the BBC reported.

The men were arrested in London, Essex and Bedfordshire after the Rwandan government requested they be extradited.

They are due to reappear before the court Jan. 26.

Emmanuel Nteziryayo, who was arrested Thursday in Manchester, was expected to appear before the London court Friday.

The men are accused of playing key roles in the slaughter of up to 1 million Tutsi villagers and politically moderate Hutus from April to July 1994 in Rwanda.

The Rwandan government said the four men will face charges of planning genocide and crimes against humanity.