British officials stated that England-born Khalid Masood, 52, is responsible for yesterday's attack in Central London, which left four people dead and injured more than 40 others, NPR reports. The dead include a woman in her 40s, a man in his 70s, and Utah resident Kurt Cochran.

Masood was fatally shot by police after stabbing an unarmed officer to death. He is believed to have acted alone, the station reports.

Police say [Masood] "was not the subject of any current investigations and there was no prior intelligence about his intent to mount a terrorist attack." ...

"Our working assumption is that the attacker was inspired by Islamist ideology," [Prime Minister Theresa May] said.

ISIS has claimed responsibility for the attack, through a media outlet with ties to the extremist group. In a brief statement, it called the attacker an ISIS soldier — but the British government says a direct link with ISIS has not been confirmed.

Calling it "an attack on free people everywhere," May said, "We are not afraid, and our resolve will never waver in the face of terrorism."

"The authorities raided six properties across the country on Thursday, detaining eight people in London and in Birmingham," The New York Times reports.

People have taken to Twitter to denounce simmering Islamophobia after Masood's name was released: