FREDERICK, Md. (AP) — A Maryland county’s public transit agency says it has taken all its electric buses out of service after a fire linked to the battery pack on one of the vehicles.

TransIT Services of Frederick County spokeswoman Kendall Tiffany said in an email Thursday that the manufacturer is inspecting all five electric vehicles in the fleet.

She says the fire Tuesday in Frederick was contained in the lithium-ion battery pack on the roof. No passengers were aboard.

Lithium-ion batteries have been linked to fires in some smartphones and hoverboards, and aboard several cargo jets.

The agency put the buses in service in May after buying them from Complete Coach Works of Riverside, California. The company retrofits older buses with batteries.

Company spokeswoman Celeste Casas declined to comment, citing the continuing investigation.