Canadian police arrested two Muslims driving an illegal load of red phosphorus, a chemical that can be used to generate phosphene gas among other nefarious purposes—and let them go: Kakebeka Falls Incident Attracts U.S Security Attention.

An incident in Kakabeka Falls last month has apparently caught the attention of the U.S. Department of Homeland Security and the F.B.I.

ABC News reports that the arrest of two people driving a van loaded 12 drums of red phosphorous has caused concern because of fears of a new terror attack in the U.S. The chemical is highly incendiary, and ABC says American authorities have reports a spectacular attack may be planned for sometime before the Presidential election this fall.

Thunder Bay Police charged a man and a woman only for violations of the Dangerous Goods Act. Police spokesperson Chris Adams says it’s an ongoing drug investigation, since red phosphorous can be used to make Speed. He says U.S. officials have not contacted Thunder Bay, but may have picked up on the case through Interpol.

ABC reports the two people arrested here were Muslims, and that they claimed they were paid $4500 to drive the phosphorous to the U.S. Adams says that in fact, they said they were paid to drive the van to Toronto. They were released with a court appearance set for July.