A black equal rights activist was shot in the head when a group of four men opened fire at a party, police have said.

Sasha Johnson remains in a “critical condition” in hospital after the shooting in Peckham, south-east London, in the early hours of Sunday.

The Metropolitan Police said a group of four black men in dark clothing had entered the garden where the party was being held and “discharged a firearm”.

In a statement, Commander Alison Heydari said: “This was a shocking incident that has left a young woman with very serious injuries.

“We are aware of Sasha’s involvement in the Black Lives Matter movement in the UK and I understand the concern this will cause to some communities – however I wish to stress that at this time there is nothing to suggest Sasha was the victim of a targeted attack.

“We are also not aware of any reports of threats made against her prior to this incident.”

The Met said that Ms Johnson was among around 30 guests at a party in the back garden of a house in Consort Road early on Sunday morning.

The group of men got into the garden through a side entrance shortly before 3am and in the “ensuing melee” Ms Johnson was shot, it added.

Detective Chief Inspector Richard Leonard said: “We know there was an organised party taking place in the back garden of an address in Consort Road.

“Sasha was among around 30 guests at the party.

“Shortly before 3am, four black males wearing dark clothing have gained entry into the garden through a side entrance and in the ensuing melee a firearm has been discharged, injuring Sasha.

“The suspects have then fled the garden.”

Scotland Yard said that a man, believed to be in his 20s, who also suffered a “superficial” knife injury during the incident, has been discharged from hospital.

Police are urging people to come forward with any information relating to the shooting and said the attackers did not deserve to be protected.

Superintendent Kris Wright added: “I would also appeal directly to the community – if you have any information that could assist this investigation, no matter how small you think it is, then please contact police or the independent charity Crimestoppers.

“Sasha has been left critically injured and her family is distraught; the people who have carried out such a callous attack do not deserve to be protected and must be apprehended.

“Please do the right thing.”

Ms Johnson is a known figure in the Black Lives Matter movement and is described as “a strong, powerful voice for our people and our community” by the Taking The Initiative Party, of which she is a member.

She works in activism and community support and got a first in social care.

Ms Johnson’s friend Imarn Ayton told BBC News that the young mother has successfully undergone surgery and her parents are with her in hospital.

Asked about the circumstances, she said: “As far as we are aware, she was at a party.

“There was a rival gang that may have heard about someone being in that party that they didn’t feel quite comfortable with or trusted and so they resorted to driving past and shooting into the garden, and one of those shots obviously hit Sasha Johnson.

“But I don’t believe she was the intended victim.”

On Monday, a group gathered around the bandstand in Ruskin Park, Denmark Hill, to hold a vigil for Ms Johnson close to the hospital where she is being treated.

They played African drums and prayed for Ms Johnson to pull through.

Witnesses should call the police on 101 quoting reference CAD1172/23MAY or Crimestoppers anonymously on 0800 555 111.