The Metropolitan Police Service in London said an attack near the Houses of Parliament is being treated as "a terrorist incident until we know otherwise," according to reports from ABC News. As police assess the situation, David Lidington, leader of the House of Commons told members of Parliament that a police officer was stabbed and an "alleged assailant was shot by armed police."
President Trump has been briefed on the situation in London. In the meantime, the State Department encourages Americans in London to "exercise caution," according to ABC News.
U.S. State Department spokesman Mark Toner said, "We stand ready to assist in any way the U.K. authorities would find helpful," according to the AP. Toner added the State Department is closely monitoring the incident and urged Americans to avoid the area where the incident took place.
The BBC reports an eyewitness saw someone driving a car on the Westminster Bridge appeared to hit bystanders. London Police said the incident was reported at about 2:40 p.m. An updated report from the BBC says a woman died at the scene.
The London Ambulance Service released a statement saying, "We have declared a major incident and our priority is to assess patients and ensure that they are treated and taken to hospital as soon as possible."
The statement also mentions that the London Ambulance Service dispatched ambulance crews, London's Air Ambulance, and Hazardous Area Response Team to the scene of the incident. The first crew arrived at the Westminster Bridge within six minutes of reports of an accident. A witness named Richard Price told ABC News a "car appeared to jump the curb, knocking people over."
BBC reports a doctor at St. Thomas Hospital said some of the victims have "catastrophic" injuries. A police officer in his 30s with a head injury was reportedly taken to King's College Hospital. Junior doctor Colleen Anderson from St. Thomas Hospital told BBC "some had injuries they could walk away from or who have life-changing injuries. There were maybe a dozen [injured]."
Regarding the incident at the House of Commons, NBC News reports journalists heard "gunshots shortly after 2:30 PM and were told to stay in their offices." British author and journalist Quentin Letts told MSNBC the police acted "incredibly fast" after noticing a man wielding a weapon entering the security gate at the House of Commons. Parliament remains on lockdown until further notice, according to ABC News.