A woman was killed and five other people were wounded in a knife attack in central London and the police are exploring the possibility of terrorism, authorities said Wednesday.
Police were called to reports of a man in possession of a knife attacking people in central Russell Square around 10:30 p.m. (2130 GMT).
Officers attending the incident found up to six people injured, including a woman who was treated at the scene but was pronounced dead a short time later.
A 19-year-old man was arrested and a Taser was discharged by one of the arresting officers, according to London Metropolitan Police.
Mark Rowley, Met Assistant Commissioner for specialist operations, said initial investigation found that mental health was a "significant factor" in the events, adding that "of course at this stage we should keep an open mind regarding motive and consequently terrorism as a motivation remains .. one line of inquiry for us to explore."
The attack came on the same day the Met announced to increase the number of armed patrols in London in face of heightened terror alert.
Met Chief Sir Bernard Hogan-Howe on Sunday warned that a terror attack in Britain was a case of "when, not if."
The London attack followed a series of terrorist attacks in France and Germany.