Updated at 5:10 p.m. ET
In a midday attack near the U.K. Parliament building, an assailant killed two civilians and a police officer before being shot to death, British authorities say.
At least 20 people were injured in the attack, which police describe as a terrorist incident. Authorities say they believe there was a single attacker, driving a vehicle and armed with at least one knife.
Prime Minister Theresa May condemned the attack as "sick and depraved" in remarks on Wednesday evening.