Tsunami waves caused by a giant underwater volcanic eruption have hit the Pacific country of Tonga.

Social media footage showed water washing through a church and several homes, and witnesses said ash was falling over the capital, Nuku’alofa.

A tsunami warning sent residents scrambling to higher ground.

The eruption of the Hunga Tonga-Hunga Haʻapai volcano sent shockwaves across the South Pacific.

Tonga’s capital lies just 65km north of the volcano.

One Tongan resident, Mere Taufa, said the eruption hit as her family was preparing for dinner, and her younger brother thought bombs were exploding nearby.

“My first instinct was to take cover under the table, I grabbed my little sister, and screamed at my parents and others in the house to do the same,” New Zealand news site Stuff.co.nz quoted her as saying.

Ms Taufa said the next thing she knew, water was rushing into their home.

“You could just hear screams everywhere, people screaming for safety, for everyone to get to higher ground,” she added.

The plumes of gas, smoke and ash pouring from the volcano reached 20km into the sky, Tonga Geological Services said.

The eight-minute eruption was so violent it could be heard as “loud thunder sounds” in Fiji, more than 800km (500 miles) away, according to officials in the capital Suva. The Fijian Government has advised people in low-lying coastal areas to leave, and opened evacuation centres.
In New Zealand, which is more than 2,300km away, officials have warned of storm surges.

The National Emergency Management Agency said coastal areas on the north and east coast of the North Island could see “strong and unusual currents and unpredictable surges at the shore”.

Local forecaster Weather Watch tweeted: “The energy release is simply astonishing”, adding: “Reports of people hearing the sonic booms across New Zealand.”