In the South Atlantic, British forces were stretched by the cruise of "Admiral Graf Spee", which sank nine merchant ships of in the South Atlantic and Indian Ocean during the first three months of war. The British and French formed a series of hunting groups including three battlecruisers, three aircraft carriers, and 15 cruisers to seek the raider and her sister "Deutschland", which was operating in the North Atlantic. These hunting groups had no success until "Admiral Graf Spee" was caught off the mouth of the River Plate between Argentina and Uruguay by an inferior British force. After suffering damage in the subsequent action, she took shelter in neutral Montevideo harbour and was scuttled on 17 December 1939.