Wal-Mart Stores Inc. (WMT) on Tuesday maintained its September sales forecast but repeated that the aftermath of Hurricane Katrina could hurt the final number and said 17 of its locations remained closed.

The world's largest retailer said that sales last week showed greater gains in food than in general merchandise, and that sales in the South were stronger than in other regions.

The company last week had projected a September increase of 2 percent to 4 percent in sales at stores open at least a year.

Wal-Mart had warned last month that steep oil prices were curbing consumer spending, which would hurt second-half results. The hurricane has driven oil prices even higher, putting more pressure on Wal-Mart's core low-income shoppers.

The retailer said 10 of its supercenters, three discount stores, four Sam's Club (search) warehouse clubs and one corporate facility remained closed as of Tuesday morning, although the company expected to reopen the corporate facility later in the day.

Wal-Mart had closed as many as 126 locations in the path of Hurricane Katrina.

On Thursday, Wal-Mart released its sales for August, reporting an increase in same-store sales of 3.3 percent, lower than the 3.4 consensus from analysts surveyed by Thomson Financial. The company then had also projected the 2 percent to 4 percent increase for September and cautioned that oil prices and Katrina's effects could hurt sales.

Wal-Mart had August sales of $23.33 billion.

The Bentonville-based company is to release its September sales numbers on Oct. 6.

Reuters and the Associated Press contributed to this report.