Police are appealing for information after a 39-year-old woman was slashed in a knife attack at Speakers' Corner in London's Hyde Park.
The woman was named on social media as Hatun Tash, a former Muslim, who is now a Christian speaker.
The Met police said they were called by the London Ambulance Service (LAS) at around 3:30 p.m. on Sunday to reports of an assault and found a woman who'd sustained a minor slash injury to her head.
She was treated at the scene by the LAS before being taken to a central London hospital. Her injuries are not life-threatening.
Following a search of the area, a knife was recovered nearby.
People of different faiths often gather at the Speakers' Corner landmark for public debate.
Detective Superintendent Alex Bingley, from the Central West Command Unit, which covers policing in Westminster, said in a statement: "This was clearly a very distressing incident for the woman involved and officers have spent time with her, whilst she was being treated for her injury, to get an account of what happened.
"We know that this assault was witnessed by a number of people, many of whom captured it on their phones. I would ask them, if they have not already done so, to contact police.
"We remain in the early stages of our investigation and are working hard to trace the person responsible. I would ask people not to speculate on the motive for the attack until we have established the full facts."
The Met police told Premier they aren't releasing the name of the woman attacked.