Masked raiders threatened a night watchman with a Samurai-type sword and tied him up in a robbery at a factory last night.

The two raiders punched and trussed him up with cable and fled in a stolen car after breaking into Unova UK, Landis Lund factory at Eastburn near Keighley.

Both robbers were wearing black ski masks and rubber hospital gloves in the raid, which happened between 8pm and 9.30pm.

The 38 year-old security guard suffered minor injuries and was treated at Airedale General Hospital, Steeton.

Detective Chief Inspector Roger Gasson, of Keighley police, said: "The robbers confronted him on the shop floor as he was doing his rounds.

"They punched him and tied him up with electrical cable. One of the men was carrying a Samurai sword."

The men made their escape with valuable computers in a car they stole from the premises.

Scenes of crimes officers were still evaluating how much had been stolen, said Det Chief Insp Gasson.

Both wore black clothing. One is described as more than 6ft tall of stocky build wearing black jeans, black fleece jacket and black trainers. He was carrying the Samurai-type sword with brown string round a white handle.

The second man was smaller and also wearing a grey canvas coat with a hood and black jeans.

They escaped in a red Ford Focus, registration YJ02 EZM.

It is the second time in four months that raiders have struck at the engineering plant.

In November men attacked a guard and threatened him with a knife and gun, before tying him up and stealing equipment.