A leak at the Co-op refinery in Regina prompted a full evacuation of the site Thursday.

Federated Co-operatives Limited says the evacuation was a necessary precaution after a small localized leak was detected at the refinery complex around 11 a.m.

The company tweeted that all of the nearly 1,200 workers forced from the site are safe. Employees were given the all-clear to return just before 1 p.m.

There were no environmental impacts, the company said, and the incident was not expected to have a significant impact on production at the refinery. An investigation is being conducted into the cause of the leak.

In May, the company that runs the refinery, Consumers’ Co-operative Refineries Ltd., was fined $280,000 after pleading guilty to an occupational health and safety violation stemming from a 2011 explosion. It was the fourth fire at the refinery in the span of about two years.

The blast injured 52 people, 13 of whom needed immediate medical attention. The injured workers have since filed a lawsuit alleging negligence put them at risk. None of the allegations in the lawsuit have been proven in court.