MYSTERY still surrounds the reason why swimmers fell ill after swimming in the sea off north Essex.

Hundreds of families were enjoying the sun in Clacton, Frinton and Walton on the hottest late August bank holiday weekend on record when a large number of people began to have trouble breathing.

Essex Police are investigating, but the cause remains unknown.

Emergency services, including the ambulance and fire service, were called to the seafront off Fourth Avenue shortly after 2pm on Sunday.

A "small" number of people were taken to hospital for further evaluation, in a stable and non-life-threatening condition.

Despite speculation of a fuel spill from a ship, the Maritime and Coastguard Agency, which sent a counter surveillance pollution aircraft to the scene, said no evidence of this has been found.

Clacton MP Giles Watling said: “I’ve been in touch with the Home Secretary and we are jointly looking into the details of what has happened.

“At this stage establishing the facts and ensuring that people who need support are being assisted is our priority.

“Priti Patel spent a day in Frinton last week and had a fabulous day. We need to return to normal as soon as possible.

“I have spoken to local residents who are still enjoying this great weather on our wonderful coastline.”

Steph Saunders, 33, of North Road, Brightlingsea, was very concerned after her daughter Rose, 8, complained of a tight chest after they went searching for sharks' teeth in Frinton.

She said: "We were just paddling in the water for about an hour and when we got out my little girl said; 'my chest really hurts' and she straight away starting coughing.

"She wouldn't have swallowed any water at all as she did not get wet past her waist height.

"It is just a bit worrying, we just did not expect it at all."

Basildon Standard:

  • Beach Patrol warn people to get out of the water in Frinton. Picture: Mark Wray/PA Wire.

A mother who was on a family day out at the busy beach told how her one of her twin daughters was left "gasping" for breath.

Miriam Lansdell said: "My daughter started coughing. She said 'I don't feel good. It hurts to breathe in'. My other daughter was gasping and couldn't form words because she couldn't breathe well enough."

The 45-year-old mental health worker from Derbyshire, who was visiting her parents in Essex for the bank holiday weekend, said she had also had difficulty breathing as she lay on the sand drying off after a dip in the water.

She said they all began to breathe easier when they moved further away from the beach, but took the 10-year-old girls to a walk-in clinic to be checked over by medical staff.

Ms Lansdell said her father had been told by someone in a speedboat, who he assumed to be associated with the coastguard, that there may have been a fuel spill.

She said: "My dad said he had been asked to get out of the water by a man on a boat. He asked why and the man said there had been a fuel spill. He said if anyone is having breathing difficulties they should probably call an ambulance."

She added: "It's not what you expect when you go for a day out to the beach."

Training manager, Mark Wray, who was enjoying a day at the beach with his wife, said he had noticed a few children coughing as they came out of the sea but assumed they had swallowed some water.

He said a few hours later two men from a beach patrol started going backwards and forwards in a dinghy along a short section of the beach, about 50 feet from the shore, urging people to move back, but that there was no clear instruction to get out of the water.

He added: "Then others, with radios, began patrolling the beach and starting to tape some areas off. It was all very low-key and there didn't seem to be much urgency to it.

"But as we were heading home a procession of emergency vehicles, including ambulances, fire appliances, police cars and other unmarked vehicles with blue flashing lights started heading towards the scene."

He said the beach was "packed with hundreds of families enjoying the record-breaking temperatures"

Basildon Standard:

  • Part of Frinton beach was closed on Sunday. Picture: Mark Wray/PA Wire.

Another parent, who had brought his family from Bury St Edmunds to Frinton for the day, said: "After a short while my daughter started coughing.

"We thought she had swallowed some sea water but then we noticed a few people around us with kids coughing.

"As we went to sit for a while we noticed that everyone around us with kids were coughing. Even some teenagers.

"Myself and some other parents tried to call the police but there was no phone network.

"I had to go a fair way out to get signal and the police asked if I could see anything in the air or water, to which I said no.

"They just advised us to seek medical advice.

"As we were leaving a gentleman was complaining of the same symptoms."

Essex Police said that while the cause is investigated, people are advised not to go into the sea.

A spokesman added: "Emergency services have received reports of a large number of people suffering from coughing on the seafront in Frinton and Clacton this afternoon.

"The cause for this is currently unknown and we and our partner agencies are working to try and establish the cause as quickly as possible.

"While we are doing this, we are advising people to not go into the sea."

East of England Ambulance Service said people should wash themselves down if they were in the water, change their clothes and drink fresh water.

Anyone with further concerns is advised to call the NHS on 111.

A spokesman for the ambulance service added: "We are aware of an incident on Sunday with reports of a number of people suffering from coughing on the seafront off Fourth Avenue, Frinton.

"We are assisting the police and fire services with this incident.

"The cause is currently unknown."

A spokeswoman for the Maritime and Coastguard Agency said: "At around 2.30pm on Sunday afternoon, HM Coastguard received reports of beach swimmers suffering from a possible respiratory irritant causing people to cough at Frinton and Walton.

"The Maritime and Coastguard Agency has not received any reports of pollution being spilled in the area from vessels.

"The MCA's counter pollution surveillance aircraft has flown over the area this afternoon to undertake an aerial survey and no fuel pollution has been reported by this flight."

Earlier this month a hazardous material left several people on Worthing seafront complaining of sore eyes and vomiting, and two requiring hospital treatment.

The coastguard said a passing cargo ship might have been the cause.

An investigation was launched in August 2017 when a chemical haze in Eastbourne left 150 people needing hospital treatment for sore eyes and breathing problems.

The most likely cause of that incident was believed to have been fumes from a ship illegally flushing its tanks with chemicals.

Tendring Council said it was aware of a number of people reporting feeling unwell at beaches in Walton, Frinton and Clacton, but encouraged holidaymakers looking to make the most of the bank holiday sunshine to still visit the Essex Sunshine Coast.

Alex Porter, cabinet member for leisure and tourism, said there was no reason for people to be alarmed.

“No-one has been seriously hurt, and while work is ongoing to establish the cause it would be unwise to speculate,” he said.

“Pending the outcome of that work, current advice is to avoid going into the water, and we would encourage people to respect that.

"Our Beach Patrol teams, which will be increased on Bank Holiday Monday, will continue to advise beach goers and keep them up to date.

“There is much more to our coastline than just the sea though – we have beautiful, award-winning beaches, lovely promenades just right for a stroll in the sunshine, and glorious seafront gardens and parks just right for enjoying the sunshine.

“Coupled with numerous businesses selling cold drinks and ice creams to help visitors beat the heat, Clacton, Frinton and Walton remain good places to visit for Bank Holiday Monday.”

Tendring Council added that it is part of the multi-agency response looking to establish what the cause of the symptoms were.