The Calgary Public Library says all of its locations will reopen for regular hours on Wednesday after a cybersecurity breach hit the library system on Friday.

The attack led to all CPL locations closing as of 5 p.m. Friday. All servers and library computer access were turned off.

“Data security is a key priority for the library and our security team is working to complete a thorough investigation,” reads a statement from the CPL, issued Monday.

“While many services will not be available during this process, we are committed to providing critical access to library spaces.”

Patrons at the library on Wednesday will have access to library spaces and services that do not require technology, the CPL said.

Those services include programs and events that don’t require technology, limited access to collection browsing, limited materials check-out and holds pick-up, and limited availability to study areas and drop-in meeting rooms.

Book returns, printing, digital library access, and online room booking and program registration are among the services that won’t be available for the time being. The libary said due dates for all borrowed materials will be extended until further notice.

The CPL said there’s currently no timeline on when an investigation into the breach will be completed.

“We would like to thank our employees, volunteers, and members for their ongoing support, understanding, and dedication,” the statement reads.

Tom Keenan, a professor in the School of Architecture, Planning and Landscape at the University of Calgary, previously told CBC News public institutions such as libraries are a logical target for cyber criminals.

“Almost everybody has a library card, it’s free in Calgary, so there’s a big database of people they can get,” Keenan said.

“And think about it. When you got your library card, what did you tell them? Your name, maybe your address, your email address. So there’s a rich amount of data there and the bad guys go looking for things like that.”

Late last year, a cybersecurity incident disrupted Toronto Public Library services, and forensic investigators found the hackers stole the personal information of current and former staff members.