A suspected gas leak was being tackled tonight in Longton, near Preston.
Fire crews were called to Osbert Croft this evening after a main burst into flames.
Neighbours said gas workers were on site working in the cul de sac when it happened.
One resident said: “I heard this banging - it sounded like a car backfiring.
“I looked out of the window and there was all this cracking and popping.
“The gas main seems to be on fire - a tree and a bush have gone up and flames are shooting into the air.”
A Lancashire police spokesman said the force had been alerted but no evacuations had been ordered.