BARRIE, ONT. -- Environment Canada is investigating how an unintentional tornado warning was issued Tuesday morning for several parts of southern Ontario, including Grey Bruce.

Environment Canada's Geoff Coulson tells CTV News the alert was the result of a testing error.

Coulson said the agency was using a backup server, as they often do when "it somehow" connected to an operational system.

The same issue happened on Monday with a frost warning, which didn't raise many alarm bells.

The faux tornado warning happened just before nine and lasted about three minutes before it was cancelled.

"We are taking steps to prevent this kind of error from happening in the future," the weather agency posted online.