A father who died alongside a woman and a teenage girl after entering the sea off the Sussex coast was a Palestinian refugee called Hossam Al-Khawas, the Palestinian embassy has said.

Mr Al-Khawas is thought to have gone into the water to swim with three other family members near Shoreham Fort in Shoreham-by-Sea, West Sussex, on Tuesday afternoon.

Police, paramedics, coastguard crews and a lifeboat attended the scene where four people were pulled from the water.

Mr Al-Khawas, a woman and teenage girl were pronounced dead and a young girl was taken to hospital in a critical condition.

The father was from the Rashidieh Camp in Lebanon but the embassy said it was unable to confirm the names of the other family members.

Earlier on Wednesday, Andy Burnham warned of the dangers of open water swimming after the incident, which he described as “a terrible family tragedy”.

Mr Burnham said: “The thing I can say today – and there is still, I think, a further heatwave to come in this summer period – it is just to remind people about the dangers of open water swimming.

“The coldness, even when it feels hot outside, it can shock people and that can cause the difficulties. So people just need to remember that at all times.

“I do need to praise the emergency services who I know were on scene very quickly yesterday. They’ve had a busy summer but they were there and we thank them.”

Police have not announced the identity of the victims but said their next of kin were being supported by specialist officers. The Palestinian embassy said it was also in touch with the wider family.

In a statement on Facebook, the embassy said it was “closely monitoring the incident”.

“As the embassy extends its deepest condolences and sympathy to the victims’ family, their loved ones, and members of the Palestinian community in the United Kingdom in this painful affliction, it wishes the injured girl a speedy recovery,” the post said.

East Worthing and Shoreham MP Tom Rutland said everybody in the area was “shocked and saddened” by the incident and stressed that people need to understand the dangers of open water swimming.

Speaking near the scene on Wednesday, he said: “It’s too early to know exactly what caused yesterday’s trouble that led to the tragic deaths but I think there’s always more that can be done to educate people about water safety.

“I think people living by the sea broadly have a good understanding of the dangers it can pose, but we need to make sure that everybody in the country has that same knowledge, given that people love to come to the coast in the hot summers that we’ve been having.”