Sounds of explosions and heavy smoke have closed the area of Yonge and King streets in Toronto’s Financial District and evacuated the Royal Bank of Canada building.

Witnesses reported hearing a blast and then seeing brownish smoke rising from a sewer grate near 20 King Street West shortly after 5 p.m.

Emergency crews said a hydro vault was the cause of the explosion, but say they don’t believe there is a public safety risk. The blown hydro vault fire has since been contained.

However, officials are continuing to advise people to avoid the area as small explosions are still being heard from underground.

Toronto Hydro spokesperson Brian Buchan said that these vaults contain high-voltage transformers. Therefore, these incidents are possible in this area as these vaults and electrical equipment are stored underground.

Toronto Fire is advising people to avoid the area as they continue to investigate the situation.

It has not yet been determined what caused the blow out. But, Platoon Chief Kevin Shaw told reporters that it may have been caused by the weather.

“Typically rain, humidity, dampness seems to get into the infrastructure that may be a little bit older and deteriorate,” Shaw said. “They cause these fires.”

No one has been injured, according to officials.

Cnst. Allyson Douglas-Cook told CP24 that Toronto police are working with Toronto Fire to investigate the situation.

Currently, Front and Adelaide streets are closed at King Street. As well, King Street is closed between Yonge and Bay streets.

The TTC says subway service is bypassing King Station in both directions due to this investigation. As well, the 504 and 514 streetcars are diverting in the area.