The youngest member of a Palestinian family who got into difficulty in the sea at Shoreham has died in hospital.

Saja El-Khawas, six, died three days after she was pulled from the water on Tuesday alongside three members of her family, according to a law firm representing the hospital and the Palestinian Forum in Britain.

The family, who travelled from their home in London, are believed to have entered the sea to swim, though the circumstances surrounding the tragedy have not yet been established.

Saja’s father, Hassan El-Khawas, 55, her mother, Zeina Alayn, 37, and her 14-year-old sister, Sara El-Khawas, were previously confirmed dead.

A major emergency response involving police, paramedics and coastguard crews was launched on Tuesday afternoon after reports that people were in difficulty in the water just after 2pm.

Saja was taken to hospital following the incident and was previously said to be in a critical condition.

It has now been confirmed she died on Friday.

Saja’s identity and death were confirmed in a legal notice from solicitors acting on behalf of Guy’s and St Thomas’ NHS Foundation Trust, as well as the Palestinian Forum in Britain.

The Palestinian embassy said Mr El-Khawas was a Palestinian refugee from the Rashidieh Camp in Lebanon.

Rashidieh Camp is on the Mediterranean coast in southern Lebanon and is one of the most populous Palestinian refugee camps in the country.

The older part of the camp was built by the French government in 1936 to accommodate Armenian refugees who fled to Lebanon, while the newer part was built by the United Nations Relief and Works Agency for Palestine Refugees in the Near East in 1963 for Palestine refugees, according to the agency.

On Wednesday, Sussex Police said their investigation remains open, but after a review of CCTV footage and initial witness accounts, it is currently thought the deaths were a tragic accident, with no third-party involvement.

Chief Superintendent James Collis said: “The events of Tuesday afternoon are a heartbreaking tragedy which has devastated a family and their friends and had a profound impact on the Shoreham community.”

Ellen Wilkinson School for Girls posted a tribute to Year 8 student Sara following the “tragic incident” during the summer holidays on its website on Thursday.

The school, in the London borough of Ealing, said: “Sara was a sweet girl, well-liked by staff and students and she will be greatly missed.

“Our thoughts and heartfelt condolences are with her family, friends, and all those affected.

“This news will be deeply upsetting for many students, families and staff.”