An American woman was killed in Wednesday's knife attack in London.The woman was believed to be in her 60s, NBC News reports . Five other people, including another American, were injured in the attack. A 19-year-old suspect is in custody.Officials told NBC that they believe mental health was a "significant factor" in the attack. There are no known ties to terrorism at this time.This article was originally published on August 3, 2016.A knife-wielding attacker in London killed one woman and injured five others in an attack that took place at 10:33 Wednesday night, the BBC reports A 19-year-old man was arrested at 10:39 local time after an officer discharged a Taser, according to the Metropolitan police . The attacker was loose for just six minutes. Initially, the woman was only injured, but she succumbed after help arrived.The police say that they’re exploring terrorism as one possible motive, though mental health issues have also been cited. The attacker struck in Russell Square, with police quickly swarming the scene. A forensic tent has been erected on nearby Southampton Row.