NEW ORLEANS -- The Coast Guard is responding to a crude oil spill from that reportedly discharged from a Shell subsea well-head flow line, approximately 90 miles south of Timbalier Island, Louisiana, Thursday.

Shell officials said they believe about 2,100 barrels (88,200 gallons) of oil were released in the spill. Authorities said Shell has isolated the leak, and the source of the discharge was reported as secured.

Shell added there are no drilling activities at the Brutus platform, close to where the leak is located, and the spill is not a well-control incident.

Kimberly Windon, a Shell spokesperson, said, "No release is acceptable, and safety remains out priority as we respond to this incident."

Marine Spill Response Corporation and Clean Gulf Associates have been contracted by Shell to begin clean-up and containment operations.

A Coast Guard Aviation Training Center Mobile HC-144 Ocean Sentry aircrew was sent to conduct an aerial assessment of the site and surrounding areas.

The cause of the leak remains under investigation.