Police have evacuated an industrial area in Castleford after a methane leak from a tanker.
Emergency services were called to Whitwood Truckstop, on California Drive, just off the M62, earlier this evening.
Roads in the immediate area have been closed and police are advising motorists to stay away.
Insp Graham Hawcroft, from West Yorkshire Police, said: "Police were called to California Drive in Castleford, following reports of a chemical leak from a tanker.
"Officers are currently working with the fire service and other partners in response to what is an ongoing incident.
"Road closures and a cordon have been put in place to contain the immediate area and drivers in this area should expect delays."