Five police officers have been injured after a number had to be recovered from the Thames when their boat hit Westminster Bridge. The patrol boat was responding to reports of a person in the water further up the river, the force said. Emergency services rushed to the incident on the River Thames after the patrol boat crashed in central London at around 3.45pm today. Three officers were thrown into the River Thames by the collision before they were rescued by those on nearby boats. Video footage, obtained by the Daily Mail, also showed individuals on the Uber Boat attempting to rescue one officer in the water. Meanwhile, two others could be seen being pulled onto the black rigid inflatable boat from the River Thames. RNLI responders could be seen treating casualties at the scene. The Metropolitan Police do not believe any members of the public were injured or involved. The cause of the incident has yet to be confirmed as the force has said their 'priority is the wellbeing of the officers involved'. The Metropolitan Police's Marine Policing Unit is not routinely armed, but they do work with armed officers from the Specialist Firearms Command (SCO19).The two units work alongside each other to handle high-risk security, counter-terrorism and armed response operations on the Thames. Several officers entered the water but were recovered and were seen being treated by paramedics on a rigid black inflatable boat moored to the side of the river.Officers have taped off a section of the bridge overlooking the Houses of Parliament, and have since cleared members of the public from the area.A police cordon was placed at either end of the bridge and buses and coaches travelling on it were forced to reverse and find another route. Five police officers have been injured after a number had to be recovered from the River Thames when their boat hit Westminster Bridge A police cordon is in place at Westminster Bridge, with a large emergency service presence Police cars and a fire engine are seen parked on Westminster Bridge on Friday afternoon Pictured: The police boat being towed down the River Thames following the crash today An area cordoned off by police near the site where a boat of the Metropolitan Police's Marine Policing Unit (MPU) struck Westminster Bridge A large number of officers, fire crews and ambulances are on the scene, with an air ambulance and police helicopter spotted circling above earlier.Mother and son Cecilia Lusevic, 56, and Mateo Bilis-Lusevic, 12, said they heard a loud bang when the police boat crashed into the bridge. The two, visiting from Chile, were on a Thames tour boat on the north side of the bridge as they saw officers being rescued from the river. 'Two boats were riding extremely fast through the water,' the 12-year-old said. 'Suddenly, I was looking towards the boat, and I heard a boom.'Then three people went flying into the water, and one of the people was really hurt.'He added that the officers were in the water for around ten minutes, and a life ring was thrown to one of them before a black rigid inflatable boat arrived to help them.Mateo said emergency services then also arrived as he and his mother were evacuated from their vessel shortly after. A US couple said they heard 'an explosion' when a police boat travelling at 'high speed' struck Westminster Bridge.Jim Bagley, from Gloucester, Massachusetts, said: 'We were standing in line to get onto the city cruise hop on, hop off tours, and we saw two police boats coming up the river.'One was an orange boat that went under the bridge and left a great big wave, and then there was a black boat that came up behind it, the police boat.'It looks to me that he got stuck in the wake of the other boat that had just passed through the bridge and slammed into the wall on the opposite side.'We didn't see it happen, but we heard the explosion… the next thing we saw was three people in the water, coming down the river.'He added: 'We were wondering why they were under way at high speed to begin with.'Katherine Bagley said: 'They were both in pursuit of something further down the river, but they never… the second boat never got to it because it crashed into the bridge with a big bang.'Entrances three and four to Westminster Underground station have been shut, Transport for London confirmed.A fire service boat has since been seen towing the black rigid inflatable police boat away from the bridge.An Uber Boat service, operated by Thames Clippers, was also cancelled and others were delayed today following the incident this afternoon. The RB1 3.26pm Battersea Power Station to Barking Riverside service was cancelled, the firm confirmed.The Port of London Authority earlier confirmed the incident at Westminster Bridge involved a police vessel.A Met spokesman said: 'At around 3.40pm on Friday, 24 July, a boat from the Met's marine policing unit struck Westminster Bridge while responding to a report of a person in the water near Battersea.'As a result of the collision, three officers were thrown from the boat into the water. They were recovered by those on nearby boats.'Additional officers responded alongside the London Ambulance Service and London Fire Brigade.'Five officers were injured and received treatment at the scene before being taken to hospital. One has since been discharged.'No members of the public were injured in the incident, the Met added. Pictured: Onlookers amid the patrol boat crash at Westminster Bridge at around 3.45pm today London Fire Brigade said its fire boat and three of its fire rescue units with water rescue capabilities were mobilised following the incident A police cordon was placed either end of the bridge and buses and coaches travelling on it were forced to reverse and find another route Emergency services at the scene near Westminster Bridge as witnesses say they heard a loud boom as the incident unfolded An Uber Boat service, operated by Thames Clippers, was also cancelled and others were delayed today following the incident this afternoon (Pictured: Emergency services at the scene) A number of officers entered the water but were recovered and have been seen being treated by paramedics on a rigid black inflatable boat moored to the side of the riverMetropolitan Police Commander Nick John said of the bridge collision: 'Our thoughts are with all those involved, in particular our officers who were injured and those who responded in challenging circumstances.'The four officers who remain in hospital have serious but non-life-threatening injuries. We will give them all every support as they recover.'I must also offer our thanks to those river users who came to the aid of the officers, as well as other police and emergency service colleagues who immediately made their way to the scene to assist.'The quick-thinking and professionalism of all those involved undoubtedly prevented any further injuries.'A Port of London Authority spokesman said: 'We are aware of an incident involving a police vessel at Westminster Bridge.'We are supporting the response by providing river traffic management assistance where needed and are working closely with the Metropolitan Police, HM Coastguard and partner agencies to manage the situation.'An RNLI spokesman said: 'Tower RNLI lifeboat attended an incident this afternoon, Friday 24 July, at Westminster Bridge. For further information please contact the Metropolitan Police.'A spokesman for Uber Boat by Thames Clippers said: 'An incident occurred in the vicinity of Westminster Bridge on Friday afternoon that did not involve Uber Boat by Thames Clippers, however some services may be subject to disruption or delay as a result.'For further information and updates please refer to the Port of London Authority or the Metropolitan Police.'London Fire Brigade said its fire boat and three of its fire rescue units with water rescue capabilities were mobilised following the incident. A London Ambulance Service spokesperson said: 'We were called at 3.47pm today (24 July) to reports of an incident on Westminster Pier, Victoria Embankment.'We sent resources to the scene including ambulance crews, incident response officers, advanced paramedics and paramedics from our hazardous area response team (HART). We also dispatched London's Air Ambulance.'