A two-alarm fire at a condo construction site at the University of British Columbia's Wesbrook Village kept Vancouver firefighters busy Sunday morning.

Crews arrived to the 5700 block of Birney Avenue at around 2 a.m. to find flames and heavy black smoke coming from a parkade connecting three buildings under construction.

After initially entering the area, multiple explosions forced crews back.

Vancouver Fire Rescue assistant chief Dan Stroup said the parkade was filled with construction materials, including propane tanks.

"We're not sure what was exploding at the time but it was unsafe for our crews to be in there," Stroup said.

<a href="https://twitter.com/VanFireRescue?ref_src=twsrc%5Etfw">@VanFireRescue</a> is battling a difficult fire at a condo development at UBC’s Wesbrook Village this morning. Crews found fire & heavy smoke in a parkade connecting 3 buildings. Multiple explosions forced firefighters out of the area. They will be on scene for several hours. <a href="https://t.co/ueGPUj0i9i">pic.twitter.com/ueGPUj0i9i</a> —@CoryCorreia

After taking a defensive approach, firefighters prepared for another opportunity to extinguish the fire.

"Crews did an amazing job under tough circumstances. It's hundreds and hundreds of feet to get to the scene of the fire and it was a very dangerous fire," Stroup said.

The buildings may suffer from smoke and possibly water damage, Stroup said, adding that an investigator will be on scene Sunday to try and determine what caused the fire.