Three Scotland Yard officers who were stabbed Saturday have undergone surgery.
Chief Superintendent Dalwardin Babu said the officers were recovering from their injuries, according to the BBC.
The fourth officer, who sustained stab wounds and suffered a broken hand, was later discharged from the hospital.
The officers were stabbed in northwest London after they tried to detain a man after a disturbance. Police said the officers were called to an incident outside the Kingsbury Halal Butchers on Kingsbury Road on Saturday morning. They had tried to speak to the man before he ran into a butcher shop and grabbed a 12-inch knife.
One of the officers was stabbed in the stomach while another was stabbed in the leg. A third officer had suffered head injuries and a stab wound to his arm.
Meanwhile, a 32-year-old man arrested on suspicion of attempted murder is due at Westminster Magistrates' Court on Monday. The suspect, identified as Christopher Houghton, 32, of Milford Gardens, Wembley, faces a total of eight charges, including one count of actual bodily harm on a police officer and two counts of attempted grievous bodily harm on a police officer.