There have been periodic reports of cooperation between Boko Haram and ISIL’s Libyan branch. In April, the New York Times cited a U.S. general in reporting that an arms convoy believed bound for Boko Haram from Libya was intercepted in Chad, providing one of the first concrete examples of cooperation.

PROPAGANDA SUPPORT

A U.S. counter-terrorism official, however, said that American intelligence has no evidence to support that report. The region is awash in arms, and it’s nearly impossible to determine who is sending what to whom, this official said.

U.S. officials told Reuters that they assess that slicker Boko Haram videos prominently displaying Islamic State logos were produced by ISIL operatives outside the region.

“It was clear to us that there (were) not guys in Nigeria sitting at their laptop putting this stuff together,” one official said.

A senior U.S. intelligence official said that some Boko Haram fighters have traveled to Libya to “work with Islamic State elements”, and that its shadowy leader Abubakr Shekau has established a relationship with the IS Libya branch.

But another U.S. official viewed Shekau’s pledge of allegiance to ISIL leader Abu Bakr al-Baghdadi “primarily as a rebranding exercise” aimed at boosting the stature of his group, whose leaders previously said it was aligned with al-Qaeda.

U.S. officials and private experts say they fear that as the African military pressure intensifies, the extremists could shift from a regional campaign of suicide bombings, rape and pillage to striking international targets.

“The resources and intent of ISIL to attack Western targets, combined with Boko’s ability and strength in that part of Africa is a mix that causes great concern,” another U.S. official said.

Senator Chris Murphy, a Foreign Relations Committee member, said that whatever its cooperation with Islamic State, Boko Haram is so deadly that Nigeria and its neighbours should get U.S. help to crush the group.

“I think we have an interest in combating this group regardless of their connection to ISIL,” he said.

*Reported by Jonathan Landay, Warren Strobel and Phil Stewart(Reuters/Washington)