An explosion ripped a hole in an apartment building in the 2200 block of Dundas Street in East Vancouver. (CBC)

An explosion in an apartment unit on Vancouver's east side Wednesday afternoon sent three people to hospital with burns and blew out the exterior walls of the suite, fire officials said.

Thirty-five firefighters were deployed to battle a blaze triggered by the blast in the 2200 block of Dundas Street, between Templeton Drive and Garden Drive, Capt. Gabe Roder of the Vancouver fire department said.

'His skin was falling off and his face, hair, clothes melted on him.… There is nothing you can really do to help' — John, witness to apartment explosion

Vancouver police and the hazardous material team were called in after a number of people in the neighbourhood called 911 and reported hearing an explosion shortly before 5 p.m. PT.

Ten units of the building were affected by the fire, and social service officials were on hand to help residents find a place to live Wednesday night, Roder said.

Roder confirmed it was an explosion that caused the fire, but investigators were still trying to determine the cause of the blast.

Capt. Gabe Roder of the Vancouver fire department says investigators are still trying to determine the cause of the blast. (CBC)

"There was a massive fire. It did spread up to the roof area and travelled through the roof," Roder said.

Three people suffered burns and were all taken to Vancouver General Hospital, he said.

The two men and a woman who were injured were believed to be residents of the unit, some witnesses told CBC News. The three were seen running outside the building, and one man appeared to have suffered severe burns, witnesses said.

A resident, who wanted to be identified only as John, said it was a "very helpless situation" for the burned victims.

"They were all injured, but one was visibly very seriously burned, for sure," John told CBC News.

Fire crews battled a roof fire at the Tsawwassen Town Centre Mall on Friday afternoon. (CBC)

"His skin was falling off and his face, hair, clothes melted on him.… There is nothing you can really do to help," John said.

Some witnesses told CBC News the blast felt like an earthquake, and some people said they were able to hear the explosion four blocks away.

Smoke was seen coming out of a third-floor window of the four-storey building as the fire erupted. Traffic in the immediate area was being rerouted.

Firefighters were called to another fire Wednesday afternoon in Tsawwassen, a suburban community south of Vancouver.

The fire occurred late in the afternoon on the roof of the Tsawwassen Town Centre Mall near 12 Avenue and 56th Street.

Flames and thick smoke were seen billowing out of the roof. Witnesses told CBC News that workers were pouring tar on the roof when the fire erupted.

No injuries have been reported in that fire.