NEW ORLEANS, LA — The first bus returning New Orleans residents evacuated by the government as Hurricane Gustav approached made a surprise arrival in the city Thursday.

Police Maj. Michael Pfiefer said the motor coach delivered 27 people from a shelter in McKinney, Texas. Six were dropped off in LaPlace, west of New Orleans. The others were taken to their homes in New Orleans, Pfiefer said.

The driver first took his passengers to shelters in north Louisiana where their pets had been evacuated, then turned south to the New Orleans area.

“They were the happiest people I’ve ever seen,” Pfiefer said.

The unexpected arrival caught officials off-guard. Much of the city is still without electricity. The estimated 20,000 evacuees who were moved out by bus late last week were not expected to return for several days.

Officials of the Regional Transit Authority lined up buses at the Union Passenger Terminal to take people home if more buses showed up from shelters. Mayor Ray Nagin said the official return would begin Friday. As many as five shelters would open in the city for returnees who couldn’t get to their homes.

Gov. Bobby Jindal said about 300 state-chartered buses were beginning to take residents home elsewhere in the state and hundreds of others were position to roll as soon as local evacuation orders were lifted.

Meanwhile, heavy traffic was reported on highways leading into south Louisiana and a busload of insurance adjusters was spotted in Jefferson Parish. Almost 2 million people got out of the way of Gustav, which made landfall Monday at Cocodrie, about 70 miles southwest of New Orleans.

In Plaquemines Parish, local government spokeswoman Karen Boudrie said a levee breach that flooded farmland is nearly plugged. She said residents were being allowed into the parish’s hard-hit southern end, where the Mississippi River empties into the Gulf of Mexico.

Federal levees rebuilt after Hurricane Katrina continued to hold, and only minor glitches were reported with the massive drainage pumps installed at New Orleans canals after the August 2005 hurricane. Much of New Orleans is below sea level and depends on the pumps, built by Florida-based Moving Water Inc., to keep water flowing into Lake Pontchartrain.

More than 800,000 customers were still without power, including much of New Orleans, Baton Rouge and coastal communities, Louisiana utilities reported. Entergy Mississippi reported about 10,000 customers still without power.

The emerging challenge for many evacuees Thursday was finding food and fuel. Some grocery stores had reopened and charitable groups were serving food. Gas stations reported long lines on highways leading into the area.

Lines formed at a Breaux Mart store only minutes after the Uptown grocery store reopened Thursday morning, with plywood still covering its doors and windows. The store had to discard most of its meat and poultry but still had plenty of packaged food on its shelves.

Pam Carr, 48, smiled as she wandered through the store’s aisles, grabbing produce to replace what spoiled when Gustav knocked out her power.

“Compared to Katrina, it’s a blessing to be able to come back a few days after the storm,” she said.

At a nearby pharmacy, Allyson Robinson, 54, was helping her 80-year-old mother, Shirley Alexis, fill a prescription. That was one of their first errands since returning from Baton Rouge on Wednesday.

“I live on cokes and cigarettes, so that’s all I need,” Robinson said with a laugh. “The biggest thing is ice. I doubt most people have that.”

The National Guard was expected to begin distributing ice Thursday in the area.

Lucky’s Bar on St. Charles Avenue was open and serving up cheeseburgers and fries early Thursday.

“I told my boss that we were looking at no power, and this business got power quite early,” said bartender James Collins. “We called him up and said, ‘Look. You have power. Let’s feed people who don’t have food.”