RAM-RAIDERS escaped with property worth thousands from a Kirklees firm.
Police believe the thieves used a car to break through doors at the unit in Heckmondwike Trade Centre in New North Road.
The intruders escaped with four motorbikes, two quad bikes, tools and about £1,000 cash from the lock-up.
Police believe the same thieves also broke into two neighbouring units, stealing two compressors.
The stolen quad bikes were a blue and black Yamaha and an green Apache.
The motorbikes were a pink and white Yamaha PW80, a pink and white Yamaha RT100, a green Kawasaki KMX 200 and a red Honda MTX 125, all of which had new seat covers.
A West Yorkshire Police spokesman said a man had called police on Wednesday at 11am to say he had seen someone in Moorside Avenue, Dewsbury Moor, riding a green motorbike which he thought was stolen.
The bike was seen later in Batley Carr in Town Street, near the junction with Mill Street.
Police want to trace the rider of the green motorbike or speak to anyone who may have seen the motorbikes.
Contact PC Richard Shires on 0845 6060606 or Crimestoppers anonymously on 0800 555 111.