RICHMOND HILL, Ont. -- A tip from the Canadian and American border agencies has led to the arrests of two men accused of possessing explosive materials, but authorities said the case was not related to national security.

York Regional Police said the men -- Reza Mohammadiasl, 47, and Mahyar Mohammadiasl, 18, -- were arrested Monday at a home in Richmond Hill, Ont.

Police said the investigation was launched last Thursday after a tip from Canada Border Services Agency and U.S. Customs and Border Protection.

Officers searched the home on Friday and found hazardous, explosive materials as well as a detonator device, the force said. Neighbouring residences were evacuated as a precaution while police removed the materials.

Public Safety Minister Ralph Goodale said Tuesday the case was a local matter for the York Regional Police.

"There is no known connection to any issue related to national security," he said in Ottawa. "It is a local policing matter. Obviously they've made arrests, they've laid charges and it's up to them to comment further."

Police have asked anyone who knows the accused or who may have information that can help the investigation to come forward.