In December, the Japanese declaration of war saw "Yarra" reassigned to Southeast Asia. She left Alexandria on 9 December and reached Java on 11 January 1942, where she commenced convoy escort duties. On 5 February, the sloop escorted a convoy to Singapore; the last convoy to arrive before the city was captured by the Japanese. While en route, the convoy was attacked by Japanese aircraft: "Yarra" shot down one and damaged several others, then rescued over 1,800 soldiers from the burning troopship . On 6 February, the sloop left Singapore with a southbound convoy. "Yarra" left the convoy when near Palembang to take up the tow of the disabled destroyer , with the two ships successfully reaching Tanjong Priok.