The Coast Guard closed a 12-mile stretch of the Mississippi River at New Orleans after a collision early Wednesday between a tugboat pushing one barge and a 600-foot tanker.

No injuries were reported after the crash between the Liberian-flagged tanker Tintomara and the tug Mel Oliver, but the barge split in half and diesel could be smelled at Harrah’s casino in New Orleans, Coast Guard Petty Officer Jaclyn Young said.

The river was closed about 3:30 a.m., about 45 minutes after someone reported a strong odor of diesel coming from the river, Young said. Two boats were holding the halves of the barge in place, she said.

Young did not know what the barge was carrying, but said the cargo was “red-flagged” as hazardous.

The double-hulled tanker Tintomara, loaded with about 4.2 million gallons of biodiesel and nearly 1.3 million gallons of styrene, was not leaking, said Michael Wilson, president of Laurin Maritime (America) Inc. in Houston, which manages the ship.

He said the tanker was fully manned with a crew of 22 and was heading downriver at the time of the accident. It is owned by Whitefin Shipping Co. Ltd. of Gibraltar, he said.

“We have sent our technical director to the scene in New Orleans,” he said.

The Coast Guard was checking for pollution and investigating the accident, Young said.

Because the river was closed, the two ferries that cross the river between New Orleans’ west bank and the French Quarter and one that runs from Chalmette to the west bank could not operate.

The fresh water intake for New Orleans’ west bank is below the spill but the New Orleans Sewerage and Water Board has enough water stored to last a day to a day and a half, spokeswoman Marcia St. Martin told WWL-TV. The intake for the east bank is above the site, she said.