Four guns that mysteriously arrived in an unlocked case at a Toronto Bombardier office are no longer in the possession of police.

Toronto Police told CTV News that the four weapons – two military-grade M4 rifles and two handguns – are in the possession of “other authoritative agencies” that have taken over the matter.

Police determined that the case is not a criminal investigation and are no longer involved. They would not confirm which agency has the guns, but confirmed that the Canada Border Services Agency (CBSA) is “aware of the whereabouts” of the weapons.

Photos obtained by CTV News show that the guns were marked as property of the U.S. government. They were delivered by FedEx to Bombardier’s Downsview location on Aug. 30.

The strange delivery has raised several questions. It’s unclear how the weapons, which, according to a tracking number, originated in Spanish Fork, Utah, crossed the border. It’s also not clear why the powerful guns were sent to Bombardier, or who sent them.

No ammunition was inside the box.

A delivery receipt indicated that two cases were part of the shipment, but only one case arrived at Bombardier. It’s still not known what happened to the second case or what it contained.

Bombardier confirmed the delivery and said security personnel immediately contacted police.

On Wednesday, the CBSA said it was looking into the incident. FedEx also said it was conducting its own investigation.

With a report from CTV News Channel’s Angie Seth