As part of an operation that resulted in the Coral Sea battle, the Japanese Navy sent troops to occupy Tulagi and nearby islands in the southern Solomons. These troops—mainly members of the 3d Kure Special Naval Landing Force—occupied Tulagi on 3May, and constructed a seaplane, ship refueling, and communications base on Tulagi and the nearby islands of Gavutu, Tanambogo and Florida, all of which were soon operational. Aware of the Japanese efforts on Tulagi, the Allies' concern increased in early July when the Japanese Navy began constructing a large airfield near Lunga Point on nearby Guadalcanal. By August, the Japanese had about 900 troops on Tulagi and nearby islands, and 2,800 personnel (many of whom were Korean and Japanese construction specialists and laborers) on Guadalcanal. The airfield—when complete—would protect Japan's major base at Rabaul, threaten Allied supply and communication lines, and establish a staging area for possible future offensives against Fiji, New Caledonia, and Samoa (Operation FS).