People in the outlying northern islands of Tonga's Ha'apai group are being urged to boil water for drinking following the weekend's category five cyclone.
Cyclone Ian ripped houses from their foundations and flattened the crops, leaving the Ha'apai Island group's 8,000-strong population almost wholly dependent on imported food.
The director of the National Emergency Office says the pumped ground water supply has been restored on Lifuka and he has an assurance it is safe to drink.
But Leveni Aho says in other affected areas household tank water is being checked.
"The general thing now is that there maybe some dead animals and things outside the area . They have a tablet and then drop it into the tank and then they have these -what do you call it - like a litmus test, things you drop in there. If it turns black it means the water is contaminated."
Leveni Aho says there is no way of catching water once the tank supplies run out so addressing that while homes are rebuilt is a priority.
