Distressed members of the public looked on as a man was left with a fractured skull after he was set upon in the street by a masked armed gang of ten.
The victim was attacked by the men wearing balaclavas and wielding weapons, including baseball bats, crowbars and golf clubs.
The attackers had arrived at the scene, outside a commercial premises in Worth Way, Keighley, in three cars.
Several shocked onlookers contacted the police as the 36-year-old local man was brutally beaten.
He was left with a broken hand, as well as a skull fracture, and was rushed to Leeds General Infirmary. His injuries are described as non-life-threatening.
The area was sealed off as police forensic teams carried out an examination of the scene.
Detectives are appealing for anyone with information about the incident or the vehicles involved, to come forward.
One of the vehicles, a dark red Subaru, was found abandoned soon afterwards in a nearby street.
The other two, a dark green or blue Lexus and a green Toyota, are both still being sought.
Detective Inspector Stuart Lyons, of Bradford District CID, said: “This happened at a busy time of day beside a main road, and we received a number of calls from members of the public, who were understandably distressed at what they saw.
“Although the motive for the attack is unclear, it does appear to be a targeted assault.
“We have stepped up visible policing in that area to provide reassurance.
“We are keen to hear from anybody who has information relating to the incident or about the two vehicles that are still untraced.”
The incident happened just before 6pm on Friday. Anyone able to help should call the police on 101 and ask for DC 6316 Tom Pearman in Bradford District CID, or contact Crimestoppers anonymously on 0800 555111.