Emergency services rushed to Bletchley’s Blue Lagoon Lake at 5.25pm today after fears that another swimmer had drowned.
It is not known whether there is a fatality but the Citizen understands after a number of swimmers ignored warning signs and experienced difficulties.
Dozens of police officers are at the Drayton Road scene along with other emergency services. An air ambulance landed at 6.10pm and left 15 minutes later with casualties on board.
And eye witness said: “There are 30 or 40 people standing around the lake. Most of them are teenagers and many are in tears.”
Official warning against bathing in city lakes were given only this week after the death of 61-year-old Paul Allsop on Friday.
Mr Allsop waded into the Blue Lagoon to retrieve a child’s ball and it is understood he suffered a heart attack.
His wife’s attempt to give him mouth to mouth resuscitation failed and he was later pronounced dead.
On Saturday - just before fire crews visited the lake to give out safety advice - a young girl experienced difficulties in the water. Luckily she survived.
On Monday police warned people to avoid getting into open water, no matter how tempting it seemed in the hot weather.
Detective Inspector Matthew Darnell said: “Inland waters can be very cold no matter how warm the weather is.
“This can lead to cramp and breathing difficulties so we would urge people to take great care and be aware of the dangers.”
Despite this gang of people, mainly teenagers, were bathing in the lake immediately afterwards.