Updated from 10:44 a.m. EDTWal-Mart ( WMT) backed its prior July same-store sales guidance Monday, saying warm weather in the just-completed week and demand for back-to-school items contributed to sales. After the bell, Target ( TGT) chimed in with its own reaffirmation. Wal-Mart still expects same-store sales to rise 2% to 4%, but that's below what the company has expected from most of the other months this year. Wal-Mart reiterated that July same-store sales comparisons from last year will be difficult because sales in 2003 were helped by a government tax stimulus program. In the same period last year, U.S. same-store sales increased 4.6%. Sales for the week ended July 23 were strongest in electronics, pet supplies and food. The company said sales of household paper goods helped the week's sales due to inflation. Summer seasonal merchandise was another category that moved during the week, and the company cited warm weather. Additionally, back-to-school and back-to-college shopping contributed to sales of bedding, backpacks, athletic shoes and school uniforms. Bentonville, Ark.-based Wal-Mart said the strongest regions in the week were the Southeast and the Midwest. Traffic and average ticket were both positive, and ticket made up about two-thirds of the same-store sales increase. The company also noted that on July 21 it opened 17 new supercenters and four new discount stores. One of the supercenters was its second 99,000-square-foot store prototype, which was opened in Salt Lake City, Utah. The company didn't open any stores in June. As of June 30, Wal-Mart had 1,409 Wal-Mart stores, 1,562 supercenters, 539 Sam's Clubs and 70 Neighborhood Markets in the U.S. Sales for the four weeks ended July 30 will be released on Aug. 5. Shares of the company were recently down 40 cents, or 0.8%, to $52.76 on the New York Stock Exchange. The stock is down about 5% from a year ago.