The government of Tonga – a kingdom of 170 islands in the South Pacific region of Oceania – has declared a state of emergency as it braces for the “strongest cyclone to ever hit the country”. Tropical Cyclone Gita is expected to intensify into a Category 5 storm over the day, The Guardian reported.

Cyclone Gita hit Tonga on Monday night (local time) after wreaking havoc in Samoa and American Samoa. The Tonga Police said there was a power outage in the main island of Tongatapu, where evacuation centres have been set up. The power supply firm turned off electricity in several villages, including Makapaeo, Matahau, ‘Utulau, Ha’akame, Ha’alalo, Houma and Vaotu’u, as a precaution.

Tonga’s Fua’amotu Weather Forecasting Centre has asked residents to stay indoors as the storm is expected to bring “very destructive hurricane force winds”, news.com.au reported.

“We have not had a Category 5 cyclone strike the main island before, and everyone is wondering how strong it will be,” said Polikalepo Kefu, Tonga’s Red Cross communications manager. “Tourists have mostly evacuated or are staying in their hotels and being looked after by their heads of mission.”

At its strongest, Cyclone Gita brought winds of up to 200 kmph, the The Tongan National Emergency Management Committee said. Authorities declared an emergency to allow one lakh residents to evacuate to safety, especially those who live in flood-prone or low-lying areas.

Cyclone Gita is expected to rage over Fiji, Vanuatu and New Caledonia later in the week.