A bag that sparked a security scare west of Brisbane poses no threat, police say.

Police say a bag left at a bus stop at Ipswich, west of Brisbane, poses no threat and have re-opened the area to the public.

Police declared an emergency situation under the Public Safety Preservation Act after the bag was found about 7.20am, sparking some evacuations.

The declaration has since been revoked after specialist officers inspected the bag.