A 30-year-old man remains in custody on suspicion of murder along with two others on suspicion of assisting an offender
Three people arrested over the murder of a street cleaner stabbed to death as he tried to stop a burglar, have been released on bail.
Piotr Mikewicz, 40, was attacked on Wednesday afternoon in Shepherds Bush, west London, and was taken to hospital by air ambulance but died the next day.
Scotland Yard said six people were arrested in connection with Mikewicz's death on Thursday. A 30-year-old man arrested on suspicion of murder remains in custody at a central London police station.
Two other men and three women were all detained on suspicion of assisting an offender, with the two men and one of the women having now been bailed pending further inquiries.
Police are continuing to appeal for witnesses to the attack, while tributes have been paid to Polish national Mikewicz, who was described as "a friend to everyone with a colourful and friendly personality" by his employer, private contractor Serco.
Deputy leader of Hammersmith & Fulham council Greg Smith said Mikewicz had "courageously tried to intervene" when he saw a crime being committed.
He added: "Everyone at the council is deeply saddened by the tragic news that Piotr Mikewicz, who was one of the borough's dedicated street cleaners, has died after being stabbed by some scum of the earth who obviously has no regard for human life.
"Piotr was a hard-working man who was a friendly face to all who knew him on his regular beat."
Acting chief superintendent Peter Clilverd said in a blog that police were using "all of our available resources" to catch the killer.
Police said they did not yet have the result of a post-mortem examination, which was due to be carried out on Friday.
The local authority has opened a book of condolence and is flying the flag at Hammersmith town hall at half mast.
