It has not yet joined the M23 mutiny but nor have its commanders sought to arrest M23 people or to seize arms said to be hidden in the town.

ECONOMIST: Rebel allies of Rwanda are making rapid inroads

Europol doesn't have the authority to seize evidence or arrest suspects but, it can help with intelligence analysis and the exchange of information across the European Union's 27 members.

WSJ: U.K. Arrests Men in Horse-Meat Probe