Washington (CNN) Salman Abedi, the 22-year-old alleged Manchester bomber, traveled to Libya for three weeks, returning to the UK only days before launching his attack, according US military officials assigned to Africa Command.

That specific information has been shared between US and British intelligence services, the US officials said, adding they currently have "high confidence" the information is accurate. But they also caution a full intelligence analysis is underway, including trying to determine Abedi's communications. Any new information could change the current view.

All of this is raising questions about Abedi's travel route and how aware British authorities were of him and his movements in recent weeks. The US officials say it's possible Abedi could have traveled from the UK to a nearby country such as Tunisia, which perhaps would not have raised the same red flags as a direct route.

It's relatively easy to cross the Libya-Tunisia border over land. It's also possible to travel via commercial air routes into Libya from a UK departure point.

It also raises questions about what he was doing there, whom he met with and whether he received training or support. Africa Command, which oversees any US military involvement in Libya and has extensive contacts with government and militia groups there, is now trying to use those contacts to learn where Abedi went and who he might have met with, the US military officials said. Abedi is believed to have family members still in Libya, but so far, the US has not been able to determine where they are.

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