A fourth person was also stabbed at the barn party in Begwary, on the Cambridgeshire/Bedfordshire border, at around 2.30am. The victims, all aged in their early 20s and from Bedford, travelled by taxi to the rave, which attracted around 200 people after being advertised on social media sites. At least one victim travelled to hospital by taxi and ambulance crews attended. Police were not alerted until around 3.50am. One of the victims is recovering at home. Officers say initial reports suggest there were three attackers, aged in their late 20s, and want to trace a blue Vauxhall Vectra, with the registration plate NH07BXB, in and around Begwary, later in Bedford and in particular near Bedford Hospital.Detective Inspector Jerry Waite said: Clearly there were a large number of people at this event who may or may not have known the victims or offenders but we are keen to trace anyone who was present and could help the police investigation into what happened. We are not interested at this stage in whether the party was a private affair or not, we just want people to come forward if they were there. Three young men are critically ill in hospital having suffered life threatening stab wounds so it is vital we establish the facts surrounding this incident. Two people have been arrested in connection with their attempted murder but our investigation is in the early stages and we believe others were also present or involved. Anyone who has information must come forward, anything you say will be treated in strictest confidence. INFORMATION: Anyone with information should contact Bedfordshire police in confidence on 101, or text information to 07786 200011. Alternatively contact Crimestoppers, anonymously, on 0800 555 111.