Black Lives Matter activist Sasha Johnson is critically ill after being shot in the head in south London in the early hours of Sunday, her political party said.
London's Metropolitan Police appealed for witnesses after offices found a woman, who they said was thought to be in her 20s, suffering a gunshot injury in Peckham.
Police said the woman, who they have not named, remained in hospital with life-threatening injuries.
"We are all hoping that this young woman's condition improves," detective chief inspector Jimi Tele said.
"Our investigation is in its early stages and urgent enquiries are under way to establish the circumstances."
Johnson, a mother of two, has been a leading figure in the Black Lives Matter movement in the UK and is a member of the Taking the Initiative Party's executive leadership committee, the party said on its Instagram account.
"The attack happened in the early hours of this morning, following numerous death threats as a result of her activism," the party said.
A friend of Johnson's told the BBC, however, that she thought the incident was more related to rival gangs than her activism, and she believed Johnson was not the intended victim.
(Reporting by Paul Sandle, editing by Andy Bruce)
