A house is on fire after a large explosion was heard across Christchurch.

Police said emergency services were responding to an incident at Marble Court, Northwood, where a house is on fire.

St John said five people were being treated for minor to moderate injuries.

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People took to social media to report about the explosion.

Didn't hear the explosion myself but the garage door went bang and I thought it might've been an earthquake.

— Kelly (@Tera_Argentis) July 18, 2019

Ok so it got updated to an explosion by the time I pasted it. Scary

— Nicola (@Coffeeperfavore) July 18, 2019

Police are assisting with evacuations and road closures.

Motorists are advised to follow diversions and avoid the area.

More soon...

Video Credit: James Looyer.