French police officers on Monday arrested a Rwandan believed to be a leader of a movement involved in a recent terrorist campaign in the Kivu region of Congo in which thousands of civilians have been killed and raped. Armed with an arrest warrant from the International Criminal Court in The Hague, the police detained the Rwandan, Callixte Mbarushimana, 47, shortly after dawn at his home in Paris, a court official said. He is wanted on charges of war crimes and crimes against humanity, according to a statement from the court. The Rwandan's activities had been tracked for more than 18 months in several countries, including France, Germany, Congo and Rwanda, the court official said. A court must decide whether Mbarushimana, who has the status of political refugee and has lived in France for several years, will be transferred to the international court in The Hague. The process could take several days or more, because the decision can be appealed. The prosecutor's office in The Hague said in a statement that Mbarushimana was one of the top leaders of the Rwandan rebel group FDLR, that from its base in Congo was fighting to gain power in Rwanda and was using widespread crimes against civilians to demonstrate its power. 'In 2009, the FDLR leadership decided to attack civilians in the North and South Kivu provinces in order to create a massive humanitarian catastrophe; the FDLR then tried to blackmail the international community and to extort concessions of power, in exchange for ending the atrocities,' the statement said. 'As a result of this deadly blackmail, victims were killed, raped and forcibly displaced, and entire villages were razed to the ground.' It was Mbarushimana's job to conduct an international campaign to convince foreign governments that that the FDLR was a legitimate political group that had to be reckoned with, an official in the prosecutor's office said. The arrest, evidently some time in the making, follows an incriminating U.N. report about the intractable violence in Congo in the fight over its mineral wealth and political control in the Great Lakes Region. U.N. peacekeepers in the region have been widely criticized for failing to protect civilians. Following the report, Human Rights Watch, Amnesty International and others have repeated their calls for prosecution of the leaders in different capitals who are fueling the violence. The U.N. report on the Congo, prepared one year ago and finally released this month, paints a picture of a complex web of interests in which armies and militias from a half-dozen African countries were involved in slaughtering civilians between 1993 and 2003. By some estimates, those wars left up to 4 million people dead. The arrest of Mbarushimana is linked to a cycle of violence that took place mostly in 2009. The Hague court's chief prosecutor, Luis Moreno-Ocampo, has said that one of the hallmarks of the FDLR has been a large-scale campaign of rape to terrorize the population in the Congo's Kivu region. The prosecutor said in the statement announcing the arrest that it was a 'crucial step in efforts to prosecute the massive sexual crimes' in the Congo. He said that more than 15,000 cases of sexual violence were reported in 2009 alone. As recently as August, the FDLR was involved in committing more than 300 rapes in Northern Kivu, the statement said. One official in the prosecutor's office said there was evidence that the group was also linked to the Rwandan and Congolese fighters who stormed into the village of Luvungi in late July and gang-raped at least 200 women. According to court documents, Mbarushimana is an ethnic Hutu who fled Rwanda after the Hutu genocide of ethnic Tutsis. Many Hutu refugees reconstituted into rebel groups that carried out attacks in Rwanda in a bid to return to power. The FDLR is an offshoot of one of those rebel groups and is seeking to expand its influence through its armed wing operating in Congo. The official at The Hague prosecutor's office said the prosecutor had requested an arrest warrant for Mbarushimana on Aug. 20, and that the judges signed it on Sept. 28. But the warrant had been kept secret until the French police made their move on Monday. The official also said that Mbarushimana had lived in Paris for several years as a refugee working as a computer technician. An Interpol photo shows him as a slender man, wearing glasses, on what appears to be a wintry Paris street. 