A 19-year-old man stabbed an American woman to death and wounded five others in a knife attack on Wednesday night in central London's Russell Square, police said.
Authorities used a stun gun to subdue and then detain the suspect, who's been identified as being a Norwegian citizen of Somali heritage.
The five wounded are British, American, Israeli and Australian. None have life-threatening injuries.
London Police said their investigation "increasingly points to this tragic incident as having been triggered by mental-health issues," but, "terrorism remains one line of inquiry."
In the last three years, there have been two knife attacks in London perpetrated by people associated with radical Islamic groups.
Wednesday's attack came just hours after authorities announced London would increase the presence of armed police after recent terror attacks in Europe.
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