I would id it as the White-winged Tern with its roundish dark ear patch (earphone) and its uniform primaries and secondaries feathers of its wing. There were only a pair flying over the overgrown lallang padi field at Sg Balang. These are First winter birds
They are even smaller than the Little Terns by (2cm ) coming in at 20-24cm long only. Sometimes its very contradictory when naming. Little Tern can be seen in Malim Nawar in the hundreds.