'His hair was on fire': Barbecue warning after spate of gas bottle explosions

Anyone with a gas barbecue is being urged to get it checked, after yet another backyard blast.

It is the latest in a series of explosions that have caused damage and injury, one of four such incidences in just 24 hours.

Just after 9.10pm in Sydney, security video has shown a small flame coming from an apartment.

Moments later fire crews arrive, then there is a huge explosion.

"I saw a man and he was shaking and he appeared a bit shaken and he had doused himself in water under a neighbour's hose because his hair was on fire," said neighbour, Vanessa Wegener.

The man who occupies the apartment was hosting a party when his barbecue caught fire, then exploded.

The force of the blast destroyed everything in its path.

"It has burned the whole fence, they are going to need to replace it," said neighbour Christina Gerassis.

This was one of four gas bottle explosions in NSW overnight and the seventh in a fortnight.

Fire crew have attended similar incidences in Mittagong, Goulburn, Branxton, Toongabbie, Birrong and Bondi.

The blast in Bondi left a 35-year old man with burns to 30% of his body.

Fire NSW warned people not to get complacent with gas bottles and check them regularly.