SAINT JOHN, N.B. -- The City of Saint John, N.B., shut down its information technology systems after it says it experienced a "significant" cyber attack.

The City says in a Facebook post that the 911 communication centre is operational, but many other online services have been shut down.

It says the city website, online payment systems and customer service applications are all down.

It says officials are working to "contain and eradicate" the virus and restore the systems, but they don't yet know how long that will take.

Officials say that in the meantime, they won't be accepting payments for any services, such as water bills and parking tickets -- and no late fees will be applied once everything's back up and running.

But the city notes that most routine services remain operational.

The city has also cancelled its Council meeting scheduled for Monday evening. In a Facebook post, the city says the meeting will be rescheduled for a later date.

Cyber security expert David Shipley says this looks like a highly sophisticated attack and that cleanup could take weeks, or even months, to complete.

"This is not somebody sitting in their basement getting their kicks," Shipley said."This is likely organized crime, very professional, highly motivated, highly skilled, and they're likely causing a lot of havoc."

It's not yet known whether any personal information stored on the networks have been compromised, but the city is advising that those who regularly use the systems to keep an eye on their banking and credit card information --- as a precaution.

The city also says it's coordinating with provincial and federal agencies.

"This is a conversation for the federal government, provincial government and cities to have because this will not be the last city," Shipley said."It is, to my knowledge, the biggest Canadian city so far to go to one of these attacks, but it's not the last."

This report by The Canadian Press was first published Nov. 15, 2020.

With files from CTV Atlantic's Laura Lyall.