-- Police presence on the streets of London increased today after an American woman was killed and five other people were injured in a knife attack in London's Russell Square Wednesday night, authorities said.
Of the five injured victims, one remains in hospital today -- a British man who suffered a stab wound to his stomach, police said.
The other four victims -- an American man, an Australian woman, an Australian man and an Israeli woman, also suffered stab wounds but have since been discharged.
Armed police responded to the scene within six minutes Wednesday night and the suspect, a 19-year-old Norwegian national of Somali origin, was Tasered and taken into custody. No shots were fired.
The investigation is ongoing. Officers have searched an address in north London today and will search another in south London.
Metropolitan Police's Rowley said today there is an "increased presence on the streets of officers, including armed officers."
"We would urge the public to remain calm, alert and vigilant," Rowley said.
ABC News' Darren Reynolds, William Gretsky and Rachel Katz contributed to this report.