Ottawa's police stations were in lockdown for nearly four hours Tuesday afternoon after a Facebook message threatened to "shoot up" the station on Huntmar Drive in the city's west end.

Police sources said a woman was arrested at a home on Pickford Drive in relation to a threat to shoot officers at the Huntmar station, and that charges are expected.

No one was able to enter or leave all eight stations between 2 p.m. and 5:30 p.m. as police investigated the threat.

Officers continued to work inside the stations and members of the public were advised to stay away and were not allowed to enter.