Enbridge Inc. says flow on a pipeline through southwestern Ontario was shut down for several hours by protester activity near Cambridge, Ont.

Spokesman Graham White says the protesters partially restricted flow on Enbridge Line 7 on Sunday night by tampering with a manual valve.

White says the pipe was shut down for approximately three hours on Monday morning as a safety precaution and so that maintenance workers could inspect the valve station.

He says Enbridge has safely restarted the line — which carries various products from Sarnia to Westover — and there was no impact on client deliveries.

A Monday post by "nopipelines" on a subthread of Reddit, called r/Anarchist News, claimed responsibility for the sabotage, saying it was to protest the flow of oilsands products through pipelines in Ontario.

Enbridge's Line 9 pipeline was offline for about 90 minutes on Dec. 19 after three activists concerned about the line's environmental impacts locked themselves to a valve site on the outskirts of Sarnia.