Typhoon Kajiki is battering the coast with heavy rains and strong winds, as authorities warn it could cause flash floods and landslides.

Vietnam evacuated tens of thousands of residents from coastal areas on Monday ahead of the arrival of Typhoon Kajiki, which is expected to lash the country's central belt with gales of around 140 kmh.

Typhoon Kajiki has made landfall after Vietnam ordered more than half a million people to evacuate their homes in anticipation of widespread destruction.