A black equal rights activist is in a critical condition in hospital after being shot in the head in south London yesterday.

Police are appealing for information after Sasha Johnson, 27, was found with life-threatening injuries in Southwark at about 3am on Sunday morning.

In a statement on its Facebook page, the Taking The Initiative Party, a new political group she was part of, said: “It is with great sadness that we inform you that our own Sasha Johnson has sustained a gunshot wound to her head.

“Sasha has always been actively fighting for black people and the injustices that surround the black community, as well as being both a member of BLM and a member of Taking the Initiative Party’s executive leadership committee.

“Sasha is also a mother of three and a strong, powerful voice for our people and our community.

“Let’s all come together and pray for Sasha, pray for her recovery and show our support to her family and loved ones.”

Ms Johnson has successfully undergone surgery, but she remains in hospital with her parents by her side, a friend told BBC News.

Imarn Ayton said Ms Johnson is believed to have been a party at the time of the incident, and that a “rival gang” might 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”.

“One of those shots obviously hit Sasha Johnson,” they said, but that she was likely not “the intended victim”.

Detectives from the Met’s Specialist Crime Command (Trident) are “pursuing a number of priority lines of enquiry” – but no arrests have been made yet.

Police said the shooting had occurred “in the vicinity of a house where a party was taking place”, and a number of people may have been in the area at the time.

“While the investigation is at an early stage, there is nothing to suggest that the woman who was shot was the subject of a targeted attack or that she had received any credible threats against her prior to this incident,” officers said.

Detective Chief Inspector Jimi Tele said: “This was a shocking incident that has left a young woman with very serious injuries. Our thoughts are with her family who are being provided with support at this terribly difficult time.

“A dedicated team of detectives is working tirelessly to identify the person or persons responsible for this shooting. They are making good progress but they need the public’s help.”

Mayor of London Sadiq Khan said his “thoughts and prayers” were with Ms Johnson and her family, and urged anyone with information to come forward.

He told Sky News: “It’s really important that we give the medics the time to treat her, but also the police the time to investigate this very, very serious shooting

“The police are doing what they can to get to the bottom of this. If anyone knows anything, anything at all, please do contact the police. You can do so anonymously using the Crimestoppers number (at the bottom of this article).

“It’s really important that those responsible are caught and justice happens.”

Last August, Ms Johnson was one of the organisers of the first-ever Million People March to protest against systemic racism in the UK. During the demonstration, hundreds of people took to the streets of west London.

She said she hoped the movement would “empower the community to strive for better”.

“As a people, we’re not going to stop until we have equal rights and justice,” she said.

“Our message is listen to us, hear our words, we want sustainable and tangible change.

“We don’t just want tokenistic promises, we don’t want it to come from a hegemonic standpoint. We want it to be for the people.”

Black Lives Matter UK said on Twitter: “While Sasha wasn’t part of our organisation, she impressively founded a new black-led political party and was dedicated to resist anti-black racism.

“Any attempt to intimidate or silence her, is an attack on all of us. Touch one, touch all.

“We pray that she will pull through this and those who threatened her life are held accountable.

“Our thoughts are with her children, family, and all impacted by this senseless attack.”

BLM UK says a vigil will be held on Monday.

The Taking the Initiative Party is a political party that was registered with the Electoral Commission nearly four years ago and fielded its first candidates in May’s local elections.

Ms Johnson, who got a first in social care at Oxford university, has “an immense passion for implementing change and justice and has been actively supporting the eradication of injustices in society by attending and leading protests”, according to her page on the TTIP website.

“Although not everyone may agree with her methods, she is not afraid to stand up for what she believes in.

“She is also committed to feeding the homeless and has personally been involved in delivering food and groceries to families that are in need.”

Anybody with information should call police on 101, tweet @MetCC providing the reference CAD1172/23MAY, or contact Crimestoppers anonymously on 0800 555 111.