A stolen suitcase, thrown onto the tracks, forced the evacuation of Yonge-Bloor station on Friday morning.
TTC subway service was affected on both Line 1 and Line 2.
The incident happened around 8:30 a.m. Service resumed just before 9 a.m., causing about a half-hour of delays and crowded platforms. There was no threat to public safety, police said.
Both police and Toronto fire were called in to investigate.
Trains were turning back at Broadview and St George stations on Line 2, and Union and Eglinton stations on Line 1.
Shuttle buses were ordered.