OTTAWA -- Ottawa Public Library branches that were closed Monday following a bomb threat reopened on Tuesday, which police have described as a suspected "swatting" call.

Swatting is the practice of calling emergency responders to a location using false information. The hoax call is meant to draw a large response from police or other emergency responders. 

The threat was made Monday and prompted the closure of every open branch in the city.

Chair of the Library Board, Coun. Matt Luloff told CTV News Monday night that the threat was "vague in nature" and did not name a specific branch, so staff closed and evacuated all branches in the city out of an abundance of caution.

"Protecting our staff is our number one priority. Vague or not, we needed to take this seriously," Luloff said.

Other City buildings attached to libraries were also evacuated and closed Monday afternoon.

"City facilities that share a common location with Ottawa Public Library branches were closed and evacuated out of an abundance of caution yesterday afternoon," said to Dan Chenier, General Manager of Recreation, Cultural and Facility Services in a statement. "We expect there to be no impact to their services today."

Ottawa police are investigating. Police said Tuesday afternoon the threat came in as a suspected "swatting" call. There is no threat to public safety.

Police did not announce whether any arrests had been made. 

The Ottawa Public Library announced on social media and on its website on Monday afternoon that it was closing all of its branches until further notice due to an "emergency situation." 

The OPL later announced it had received a threat and decided to close its branches as a precaution. 

The Ottawa Public Library issued the following statement to CTV News Monday afternoon:

"Ottawa Public Library received a threat earlier today and has closed all facilities. Ottawa Police Services have been notified and are investigating. The safety of our customers and employees remains our top priority. All our open branches were safely evacuated. As the investigation is ongoing, no further information is available at this time. All OPL branches will remain closed until further notice."

Luloff told CTV News late Monday that staff believed the immediate threat had passed and work was underway to reopen libraries safely on Tuesday.