A woman has been killed and six people injured after a mass stabbing took place in Russell Square, Central London on Wednesday (August 3) night.
The Metropolitan Police confirmed to getwestlondon that up to six people, including three women and three men, were found injured in the square at around 10.39pm after "a man was seen in possession of a knife injuring people".
Two people are still currently in hospital, while the other three have been discharged.
A 19-year-old man has also been arrested by police on suspicion of murder and is currently in custody at a south London police station.
Officers attended the scene along with the London Ambulance Service and at this stage, have not ruled out terrorism as "one line of enquiry", although they believe "mental health" to have played a significant impact.
In a press conference in the early hours of Thursday (August 4), a Met police spokesperson said said: "At this stage we must keep an open mind regarding the motive and consequently terrorism as a motivation remains but one line of enquiry for us to explore."
They added counter terrorism units are supporting the investigation.
The female, believed to be in her 60s, was treated at the scene but was pronounced dead a short time later.
The Met said: "A man was arrested at 10:39pm and a Taser was discharged by one of the arresting officers. The 19-year-old is now in custody.
"Additional police units have been deployed to the area to provide reassurance."
Lauren Brittny claimed on Twitter her brother, who was among a group of students at a theatre outing, witnessed the incident.
She wrote: "Sadly my brother and his mates witnessed the stabbing in Russell Square square.
"My brother rang me at time as he was in shock. But all he said was the man quickly jogged passed him and they tried to grab an ambulance driver attention who was close by but did nothing.
"My brother was at UCL summer camp and they were returning from a theatre trip .
"His mentors were guarding them so he was unable to do much I wish he filmed the guy.
"But everyone was stunned by the situation."
Most police cordons around the area have now been lifted, although one partial road closure remains in place as police continue their investigation.
Anyone with information should contact police on 101 or call Crimestoppers anonymously on 0800 555 111.