Two men involved in a knife attack at an underpass in Renfrewshire are being urged to contact police after four others were taken to hospital.

A couple of dog walkers and a workman are also being sought as witnesses to the violence, which happened at around 2.50am on Thursday in Ferguslie Park, Paisley.

Two of the men, aged 28 and 26, managed to make their way to a nearby petrol station where emergency services were called.

A police dog then followed a blood spill to find another two men, aged 18 and 20, who were found injured at separate nearby addresses.

All four were taken to Royal Alexandra Hospital with stabbing or slashing wounds and have since been discharged.

Police are now hoping to trace two other men involved in the attack as they may too be injured.

Detective Inspector Robert Bowie, who is leading the inquiry, said: "We are still trying to trace the last two men involved.

"No-one else has come forward, however, it's possible that they too could have been injured and we need to make sure they are okay.

"Why this disturbance took place has still to be established and so with this in mind we need people to contact us with information."

The potential witnesses to the violence were spotting as police reviewed CCTV footage.

DI Bowie added: "I have no doubt that they would have seen what happened and would encourage them to contact police as what they saw could be pivotal to our enquiries.

"If for any reason they have concerns about contacting police direct, they can call Crimestoppers in confidence."