Two separate murder investigations have been launched after the deaths of residents at care centres.
A 60-year-old man died at a care centre for adults with mental health and drug abuse issues in west London on Monday night.
He was treated by paramedics after being injured shortly before midnight, but was pronounced dead at the scene.
A 44-year-old man, a fellow resident at Imperial Lodge in Lansbury Drive, Hayes, was arrested on suspicion of murder.
A witness said they had seen police vehicles and ambulances with flashing lights in the street outside the centre.
The witness, who did not want to be named, said: “I saw lots of police cars and ambulances, the lights were flashing but there weren’t sirens.”
In the second case, a 34-year-old man died from head injuries at a mental health care centre in Glen Road, Newham, east London, shortly before 4am on Tuesday.
Police are in the process of telling his family.
A 21-year-old man, who was also a resident at Newham Centre for Mental Health, has been arrested on suspicion of murder.
Anyone with information about the Hayes investigation can call police on 101 or tweet @MetCC quoting the reference CAD6884/2Jan, or to remain anonymous contact Crimestoppers on 0800 555 111 or online.
Those with information about the Plaistow investigation can contact police in the same ways but with the reference CAD751/03Jan, or contact Crimestoppers.