New Zealand’s White Island (Whakaari) volcano erupted Monday, injuring around 20 people.

The eruption began at 14:30 local time.

Around 100 people were on the island at the time, according to local media. New Zealand police later said there were fewer than 50 people on or near the island at the time of the eruption.

The authorities advised residents in the region to stay in their homes and close their windows.

New Zealand's Prime Minister Jacinda Ardern said that about 100 tourists were on or near White Island when it erupted in the afternoon.

She added that "Some of those, at this stage, are unaccounted for".

The volcano on White Island is the most active in New Zealand. The last eruption took place here in 2013.