An overnight fire at a four-story hostel in New Zealand’s capital of Wellington has killed at least six people, Prime Minister Chris Hipkins said, according to The Associated Press.

Hipkins told an AM morning news program that he understands that six people have been confirmed dead in the fire, and that there are likely to be more.

Police have said they don’t yet have an exact count of the number dead, although they believe it’s fewer than 10 people.

Emergency services were called to the Loafers Lodge hostel about 12:30 a.m. local time, according to AP.

Wellington Fire and Emergency District Manager Nick Pyatt said 52 people have been accounted for, but that a number still remained unaccounted for.

Police said the cause of the fire remained unexplained, and they would be investigating alongside fire and emergency officials.

Loafers Lodge advertises itself as an affordable place for people to stay while they are in the capital. It has 92 rooms and promotes them as being available long term.