BIXBY, OK(KJRH) - Tulsa police's bomb squad responded to a U.S. Air Force recruiting center in Bixby late Monday night for a reported explosion.

Dispatchers tell KJRH Bixby Police requested Tulsa Police's bomb squad around 10:30 PM for assistance at the recruiting center near East 103rd Street and South Memorial.

Witnesses say someone on a red motorcycle threw a backpack at the recruiting center, which then blew up. They believe it may have been a pipe bomb.

Bixby officers confirm there was an explosion at the recruiting center, but referred further questions to the FBI which will be on-scene some time Tuesday morning.

Agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives are also investigating.

Read more at KJRH's website.