Two people have been arrested on suspicion of murdering a baby who was found unresponsive on an East London bus.
Police were called by the London Ambulance service after the three-month old baby was found on a bus on Carpenter Road at the junction with High Street, in Stratford, on 28 September.
The baby was taken to an East London hospital where she was pronounced dead. A 27-year-old woman was arrested at the hospital, followed by a 52-year-old man who was arrested an address in east London later that day.
The baby has not been formally identified and a post-mortem examination is scheduled to take place at St Thomas' Hospital on 30 September.
DCI Holmes said: "The death of any child is tragic and we would appeal for anyone with information to please come forward as soon as possible to help with our enquiries."
Anyone who can help is asked to call the incident room on 020 8345 1570 or Crimestoppers anonymously on 0800 555 111.