The accident happened at around 12pm on the A59 in Gisburn between Main Street and the turning of Yarlside Lane.
A Mercedes lorry and a Vauxhall Vivaro van were involved in the incident.
A spokesman for the police said: "We are currently attending a collision in Gisburn.
"Road closures are in place on the A59 and drivers are advised to find an alternative route."
An air ambulance was called but was not needed, say the ambulance service.
More to follow