A mother and her daughter died at a beach in Essex, United Kingdom, while trying to rescue a seven-year-old boy from water, police said.

The victims were identified as Shally Rahman, 41, and Samiha Rahman, 15.

The incident occurred at Sandbank at about 5:35 p.m. on Wednesday.

Essex Police said everyone involved in the incident was related to each other and that the boy was taken to the hospital, where he remains in critical condition. 

Three other people were also taken to the hospital following the incident.

In a statement, Detective Chief Inspector Al Pitcher of Essex Police said, “My thoughts, and those of my team, are with the friends and family of the woman and girl who died yesterday.

“Since yesterday we have been working to establish the circumstances which led up to this incident. At this stage we believe they were trying to help a seven-year-old boy who had got into difficulties.

“The boy was taken to hospital where he remains in a critical condition, but the woman and teenage girl, sadly, died.”

Police said they were speaking to “dozens of witnesses” as part of the investigation and urged anyone with information to come forward.

Prime Minister Andy Burnham spoke about the tragic incident during a visit to Harlow in Essex.

He said the deaths were “very, very sad” and thanked “the emergency services who stepped in to help”.