More than 300 people were evacuated after a barbecue by the New Zealand Olympic delegation ended in a huge explosion last night.

The blast could be heard in houses more than 650 hundred metres away when two gas canisters blew up during an event Kiwi House – a base for the New Zealand Olympic committee.

Two fire engines and around 10 firefighters rushed to the scene in Granary Square, King’s Cross, at around 7.20pm and set a safety cordon 165 ft around the blast.

Mike Sweeney, 50, a photographer who lives off nearby York Way, said: “I heard a big bang while I was in my house but I thought it was the builders working. My wife said go and have a look and there were fire engines everywhere.

“We have so many young students here – something like this shouldn’t happen. It was really lucky no one was hurt or even killed. We have had students killed cycling at the King’s Cross junction, we don’t want any more to be hurt.”

No injuries were reported and the fire brigade had the situation under control by about 8.45pm.

A spokeswoman for Kiwi House said: “The fire broke out in Kiwi House yesterday evening at approximately 7.30pm and guests were swiftly and safely evacuated.

“Damage was limited to a corner of the outdoor BBQ area and the Granary Square building in which Kiwi House is located was untouched.”

“We will re-open this evening from 6pm after an outdoor BBQ fire last night temporarily closed the facility.

“The garden BBQ area will remain closed.”

The cause of the fire is under investigation.