Detectives investigating a night of mass violent disorder in central London have added a woman and three men to their wanted list.
They include a man caught on CCTV who appears to be aiming a missile at police officers who found themselves attacked by a mob in Hyde Park on Tuesday night.
Images of the four have been added to a gallery of suspects sought in connection with the widespread disorder that saw a water fight descend into chaos.
Up to 4,000 people had gathered on the banks of the Serpentine on Tuesday afternoon as the capital enjoyed the hottest day of the year so far, but the festivities turned hostile as the evening wore on.
Three people including a police officer were stabbed in the violence that spilled into Marble Arch, yards from the shops of Oxford Street. A second police officer was injured at the scene by a flying bottle.
Police are yet to make any arrests and Scotland Yard has now publicly identified eight people they want to trace.
The suspects include the man appearing to throw the object in Hyde Park and the three others who are alleged to have committed offences in the Marble Arch area.
They are wanted alongside four men, three of whom are wanted in connection with violent disorder in Hyde Park and one over trouble in Marble Arch.
Detectives from the Met's Specialist Crime and Operations' Homicide and Major Crime Command are using their expertise to track down suspects as officers pore over CCTV from the area.
Commander Nick Downing said: "We have a number of specialist officers who are reviewing hours of CCTV footage and whilst we are still in the early stages of the investigation they have been able to identify key individuals who are believed to have taken part in the disorder in some way or form.
"Detectives continue to work to identify not just these four individuals but a number of others involved.
"We are appealing to the public to help us identify the individuals in the images we are releasing, or if you are the person in the images now is your opportunity to make yourself known to police.
"As the investigation continues we are still keen to hear from any witnesses or anyone with any information about any of the incidents across London on the night of the 19th July."
That evening two 16-year-old boys were stabbed in Burgess Park, south London, and a nearby supermarket ransacked at an end-of-term water fight.
Police were also pelted with missiles when they moved in to close down an illegal rave on an east London estate. Some officers suffered minor injuries and three police vans were damaged.
Anyone with footage of the incidents in Hyde Park, Westminster, the McDonald's at Marble Arch, Westminster, Burgess Park and Malvern House, Stamford Hill Estate, Hackney is asked to send them to police via www.ukpoliceimageappeal.com or www.ukpoliceimageappeal.co.uk.