A large fire that displaced more than 100 residents and prompted a boil water advisory on May 15 in White Rock, B.C., was deliberately set, say police.

The fire started in an unoccupied condo under construction but quickly spread and damaged a nearby building that housed dozens of residents and several businesses.

Mounties say they and the White Rock Fire Department have been investigating the fire and believe it was deliberate.

"This fire and the resulting displacement of the building's residents has understandably shaken our community," said Const. Chantal Sears of the White Rock RCMP.

"The fact that it is now believed this fire was intentionally set will likely cause further distress to those residents."

The extensive efforts to put out the flames taxed the water supply of the city of 20,000, leading to a boil-water advisory for the next three days.

Many of the victims of the fire, which started at 5 a.m. PT, left with few possessions and will not be able to return to their homes for another year.

Police are asking anyone with information or who may have seen any suspicious activity to contact the White Rock RCMP at 778-593-3600 or by calling Crime Stoppers at 1-800-222-8477.