A man is seriously injured after two trucks collided in North Canterbury, causing gas to leak on the road.
Emergency services were called to the corner of Greta Rd and Scargill Valley Rd, on State Highway 1 in Greta Valley, about 9.10am on Monday.
One truck rolled and the driver was seriously injured, police said.
A St John spokesman said the person was flown to Christchurch Hospital in a serious condition.
It was not known if speed was a factor in the crash.
Greta Valley Garage owner Andrew Johannis said a gas bottle delivery truck pulled out of Village Rd, turning right to go north.
It collided with a truck and trailer unit travelling north.
"[The gas truck's] been spun around and shunted over the road. There's gas bottles everywhere. There was a big bang."
He said the community had been trying to lower the speed limit in the area.
"We've been at it for years, there's so many near misses. Pulling out of the village, we're on a bend and you can only see so far," Johannis said.
"We've got a school round the corner that's basically on the highway. It's bloody dangerous."
Mike Evans, of The Greta Valley Restaurant, Bar and Motel, said gas was leaking over the road.
Rockgas general manager Philip Dring said one of their drivers was driving the gas delivery van.
Staff from Christchurch retrieved the 40 LPG cylinders that were on the back of the truck at the time of the crash.
"Our thoughts are with the driver and his family," Dring said.
A police spokesman initially said gas cylinders being transported on one of the trucks exploded.
But Dring said that did not happen.
"Some cylinders did vent when their service valves opened slightly under impact," Dring said.