The South Pacific island nation of Tonga finished removing a thick coat of volcanic ash from its international runway on Wednesday after days of painstaking effort, clearing the way for desperately needed emergency aid to arrive in the isolated, disaster-stricken nation.

New Zealand and Australia said their aircraft carrying aid supplies departed on Thursday.

Three people were killed when the Hunga Tonga-Hunga Ha'apai volcano erupted under water on Saturday, triggering tsunami waves that obliterated homes and caused widespread flooding.

With communications down, the extent of the devastation wrought is yet to be fully realized.