Nigerian President Goodluck Jonathan pledged on Saturday to track down the "pure criminals" behind a New Year's Eve bombing in Abuja that killed at least four people, according to Reuters. There has been no claim of responsibility for the attack and the president said the perpetrators had not yet been identified. "The security people are on it. We will get to the root of the matter. I urge Nigerians to remain calm," Jonathan said speaking at a New Year's Day church service in Abuja. "To me they are pure criminals that demons are using these days, not only in Nigeria but also in acts of terrorism across the whole world." Jonathan had said on Friday that those behind the Abuja blast were the same as those behind Christmas Eve bombings in the central city of Jos, which were claimed by the Islamist sect Boko Haram. But on Saturday, the presidency said Boko Haram had not at this stage been linked to the Abuja bomb.