OSLO, June 17 (Xinhua) -- Since 2018, residents of at least 62 municipalities in Norway have been asked to boil water before drinking, the newspaper Aftenposten reported Monday.

Most of the warnings were sent in April and May, and often coincided with the melting of the snow pack, flooding or extreme weather.

At other times, contamination occurred after water pipes broke or during maintenance or faults in the waterworks.

A total of 65 people have been admitted to hospital and several thousand were probably ill at home after a holding tank for drinking water in Askoy municipality in western Norway was found to have been contaminated by the E.coli bacteria early this month, public broadcaster NRK reported on Friday.

The Norwegian Food Safety Authority (Mattilsynet) supervised 1,375 sources of drinking water in 2018.

One of the requirements for the waterworks owners is to follow a sampling plan and test the water for, among other things, E. coli.

Drinking water quality is generally good in Norway, according to Karina Kaupang, managing director of Mattilsynet.

However, the competence of the smaller waterworks is variable, she told Aftenposten.

"Some of the smallest water supply plants probably do not supply as good drinking water as we would like," she said.