Hull College was placed into lockdown and later evacuated after receiving a phone call containing bomb threats on Friday afternoon.
Police were called to the college on Friday, June 19, and attended while staff and students remained inside the secure buildings.
Hull College initially said it had initiated a full lockdown following a threatening phone call, with police assisting and all its sites secure.
The decision was later made to close the college early at 2.30pm as a precaution and everyone was safely evacuated.
In an update, the college said: “All staff and students have now been safely evacuated from Hull College. The site is safe and secure.
“Huge thanks to all students and staff for remaining calm throughout. You are true Hullraisers!
“Thank you to the police for their swift response and outstanding support.”
Humberside Police said officers were continuing to investigate the incident but believed at this stage that the threats were a hoax.
A spokesman said: “We take all threats like this extremely seriously and are investigating the incident fully.
“While initial inquiries are still ongoing, we do believe at this stage of our investigation this to be a hoax.”
Anyone with information that could assist the investigation is asked to call the police non-emergency number 101, quoting log 226 of June 19.