The Metropolitan Police have announced the launch of a murder investigation after a five-year-old British Tamil girl was stabbed to death in Mitcham, South London this week.

The victim has been named as Sayagi Sivanantham.

Police were called to her house on Tuesday to find Sayagi and a woman, reported to be her mother, suffering from knife wounds. Though Sayagi was airlifted to hospital, she was subsequently pronounced dead. The 35-year-old woman remains in a critical condition.

“Although no formal arrest has been made, at this early stage, police are not currently looking for anyone else in connection with this incident,” said the Metropolitan Police in a statement released this morning.

“This is a tragic incident and we are working very hard to fully understand what has happened,” said Detective Chief Inspector Justin Howick. “Whilst I know the effects of this incident will, understandably, shock and sadden the local community, please be reassured that we are not seeking anyone else in connection with Sayagi’s death and there is no cause for the community to be fearful or alarmed.”

“Today a family are grieving for their little girl, and we are doing everything we can to support them,” said Superintendent Richard Smith, from the Met’s South West Command Unit. “This terrible incident has left a family distraught and the local community in shock. I would like to pay tribute to the police officers and ambulance service colleagues who responded to this frightening situation and thank them for working so hard to try and save Sayagi. She will remain in our thoughts.”

The Metropolitan Police’s Specialist Crime Command (Homicide) is conducting further investigations.