The U.S. Coast Guard shut down a 10-mile stretch of the Mississippi River at New Orleans on Thursday after a Singapore-flagged vessel struck a pier near Nashville Avenue and leaked an estimated 4,200 gallons of fuel oil into the water.

The accident spread streaks of dark petroleum downriver to where the annual French Quarter Festival was just getting underway. Revelers catching the event's lunchtime acts on the wharf alongside Woldenberg Riverfront Park had to put up with oil fumes wafting from off the river. 

Petty Officer Brandon Giles said the Coast Guard received the first report about the spill at 10:30 a.m. and the sheen had spread to the Moonwalk in the French Quarter by shortly after noon, forcing the agency to shut down the 10-mile stretch of river between mile markers 91 and 101. 

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There were no injuries, and the punctured fuel tank of the Pac Antares, a general cargo vessel, was later plugged, Giles said. The vessel is now moored at the Nashville Avenue Wharf, he said.

The Coast Guard was using aircraft to spot the oil, then containment boom and skimmers to help collect it from the river, according to Cmdr. Zac Ford, of the Coast Guard. Absorbent boom had been placed around the Pac Antares, Ford said.

Cleanup efforts were complicated by a high river, at 14.5 feet, and a fast current of about six knots, he said.

He could not estimate when the river might be reopened. Parish governments downriver from the spill had been notified, he said.

The RTA shut down the ferry that runs between the French Quarter and Algiers Point, but spokeswoman Taslin Alfonzo said a bus would shuttle passengers between the two ferry terminals until the river was reopened.

Security guards at the renovated Moonwalk were advising people not to sit on the steps nearest the water because of the fumes Thursday. 

Dark bands of diesel fuel drifted past the docked Natchez riverboat and under the wharf where Alex McMurray's band performed to a large French Quarter Festival crowd.

A spokesman for the Sewerage & Water Board said the agency's water intake near Algiers had not been affected by the spill.

The Coast Guard said a team is investigating the incident.

Other organizations involved in the response included the National Response Corp., Louisiana Oil Spill Coordinator's Office, Louisiana Department of Environmental Quality and OMI Environmental Solutions.

According to a news release from the Coast Guard, as of late Thursday afternoon, "OMI Environmental Solutions continues to deploy containment boom, sorbent boom and pads around the spill to contain and collect oil. They have deployed one skimmer at the site to skim the oil off the surface of the river, and four more are en route."

Staff writers Keith Spera and Faimon A. Roberts III contributed to this report.

Follow Chad Calder on Twitter, @Chad_Calder.