NEW YORK (TheStreet) -- Shares of Gap (GPS - Get Report) were falling in after-hours trading on Thursday after the retailer said sales in August dropped 2% to $1.17 billion year-over-year.

Additionally, the company's comparable-store sales for August slipped 3% compared to a 2% decline last year.

Gap comparable-store sales fell 5% vs. a drop of 8% last year, while Banana Republic same-store sales slid 10% compared to a decline of 11% last year.

Old Navy comparable-store sales increased 1%. During the same time a year ago, they grew 6%.

"While we are pleased with the continued progress at Old Navy, we remain focused on improving results across our global brands," Gap CFO Sabrina Simmons said in a statement.

The retailer added that it is currently assessing the impact from a recent fire at its distribution center in Fishkill, NY.

"The company has activated extensive contingency plans designed to help mitigate the overall impact to the business, including leveraging its North American network of distribution centers and ship-from-store capabilities," Gap said in a statement.