A company boss was taken to hospital after being attacked at his business premises in Chorley.
The 44-year-old victim, who suffered serious facial injuries, was assaulted by two men.
The incident happened at SB Metal Recycling Ltd, one of a number of small units on the Common Bank Industrial Estate, Chorley, on Friday morning.
Police said a member of the public raised the alarm at around 7.40am.
The man was working inside his unit when he was approached by two men who attacked him with a metal bar.
The men then fled into the nearby Wallets Wood and a large-scale police search was undertaken with the assistance of the police helicopter.
However at 11am, the search teams were stood down and the men remain at large.
Police said the emergency call came in to them came in as an attempted robbery.
But they said were unclear about the motive for the attack.
The injured man, who has not been named, was taken to Royal Preston Hospital and was expected to be kept in overnight.
Det Insp Paul Rudd, from Chorley CID, said: “This was an unprovoked assault and the motive is still unknown at this time, although we believe this man has been deliberately targeted.
“An investigation is under way, but I would appeal to anybody that saw two men standing at the junction of Common Bank Lane and Woodside around 7.30am this morning to contact police.
“I am convinced the area would have been busy at this time with people going to work so I’d appeal to anyone that saw these men to come forward.”
Rumours spread that police were searching for an armed man who was wandering the area, but this was denied by police.
One person at a nearby business on the industrial estate, who asked to remain anonymous, said: “It’s been pandemonium round here. He’s been beaten up.
“Apparently two lads have come to rob him.”
The metal firm was still open for business yesterday. The sole employee working at the premises said he did not wish to say anything about the incident.
The offenders are both believed to be white and aged in their 20s.
One is described as being around 6ft 2ins tall and slim build and the other stockier and around 5ft 8ins tall.
Both were wearing dark hooded tops.
Anyone with any information should call Lancashire Police on 101. They can also contact Crimestoppers on 0800 555 111.