Essex Police have taken the "unusual step" of issuing the names and photographs of Jack Hummerstone, 18, from London, and Andre Vella, 19, from Frinton-on-Sea, and are urging anyone who knows anything about their whereabouts to contact police immediately.
Thomas Brittain, 26, from Essex, died after he was assaulted in the home of a friend, in a flat in Parkside Quarter, Colchester, at around 1.45am on Saturday.
He suffered multiple stab wounds and the provisional result from the post-mortem examination carried out is that he died from a stab wound to the chest.
The mother of a teenager killed at a party last year has asked people to 'stop hiding' to try and find his killer.
Jay Whiston would have celebrated his 18th birthday yesterday but he was stabbed at a house party on Marlowe Way in Colchester on 8th September.
Jay's mother Caroline Shearer said:
'People were brave enough to do it so be brave enough to come forward. Stop hiding like frightened children. Jay was 18 yesterday. All we could buy him were two helium balloons because someone murdered him.
It's not just affected me or Holly [his sister] it's affected the entire community.'
The teenager's sister, 25-year-old Holly Fairburn, said: "Please help the police to find Jay's killer. Please don't shield people that could devastate another family's lives as they have ours."
Today police revealed at a press conference that he was stabbed three times and that one stab penetrated his heart. DCI Simon Parks said Jay was not an intended target, he was a 'victim of mindless violence.'
The murder weapon has still not be found and police are appealing for more witnesses to come forward.
They have released an image of a red and white River Island T-shirt that they believe one of the potential murder suspects wore. The T-shirt is yet to be found. 8 people have been bailed until March in connection with the incident.
The killing has shocked neighbours in the residential street, which is located on the outskirts of Colchester.
A number of homes were sealed off on Sunday as police searched for clues.
Empty bottles of vodka and cans of lager could be seen strewn across the front gardens of properties in the street.
Marie Partner said a woman and her teenage daughter, who were hosting the party, had spoken to neighbours on Saturday to apologise in advance for any extra noise.
Ms Partner, who has lived in the street for nine years, said:
The mother and daughter took it upon themselves to tell the neighbours there was a party taking place and to apologise in advance if there was slightly more noise than normal. Usually it's very quiet around here.
It's so sad. The first I knew about it was seeing the police arrive and the area being cordoned off.
Senior investigating officer, DCI Simon Parkes, said:
This really is tragic loss of life that we, but more importantly, this boy's parents have to deal with.
This murder took place in an affluent area of Colchester and at a house party which had a garden that could cater for the 100 or so teenagers that were present.
Although we don't yet know the details of what went on, we're slowly piecing together the sequence of events that led to this boy's death.
We're speaking to those who were at the party, but we're mindful that there may have been others who left either before the stabbing or in the immediate aftermath before we arrived.
Everyone at this party is a key witness whether they saw anything or not and we would urge them to contact us. Our thoughts are very much also with this boy's family. They are being supported by our family liaison officers.