Canadian energy company Enbridge said it restarted an oil pipeline that feeds U.S. Midwest markets from Alberta after an earlier release of 1,350 barrels.

Enbridge closed its Line 4 pipeline after the release was discovered late Tuesday. The pipeline carries an average 796,000 barrels of oil sourced from Alberta to a terminal point in Wisconsin.

The company said the National Energy Board was site and cleared the company to restart the pipeline.

"All free product has been recovered and more detailed clean-up work on site will continue into next week," the company said in a Thursday statement.

When issuing its notification of the release, the company said there were no environmental or public health concerns as the spill was limited to an on-site pumping station.

The NEB confirmed in a separate statement the release was contained to the immediate site.

"There were no injuries, no fire, no nearby residences and no threat to public safety," the regulator said.

The company's safety record is under close scrutiny in the wake of a spill from its Line 6b in southern Michigan in 2010, the largest inland release of its kind in the history of the industry. The nature of the heavier grade of Canadian crude oil caused it to sink in regional waters, making clean-up operations lengthy and complex.

A "pinhole" leak was discovered earlier this week on an Enbridge pipeline in Michigan's Upper Peninsula, though no spill was associated with the incident.