While the navy took control of coastal towns, the army pushed on into the interior of the island. Janssens had been reinforced on 3 September by 1,200 mounted irregulars under Prince Prang Wedono and other Javanese militia. On 16 September Salatiga fell to the British. Janssen attacked a British force under Colonel Samuel Gibbs that day, but was repulsed. Many of the native militia killed their Dutch officers in the ensuing rout. With his effective force reduced to a handful of men, Janssens surrendered two days later, on 18 September.