Residents have described witnessing “crazy” and “stressed” scenes after eight children attending a summer camp fell ill from a suspected poisoning.

Police have been given more time to question a 76-year-old man arrested on suspicion of administering poison at Stathern Lodge in Leicestershire.

Eight children and an adult from the camp were taken to hospital on Monday but have all since been discharged. The man was detained at a local pub later that day.

People living near a village hall where the children were taken for assessment by the ambulance service have described chaotic scenes.

In the latest clarification of what happened at the camp, the force said on Friday that the adult was taken to hospital as a precaution and discharged.

Marco Smeeth, the landlord of The Anchor Inn in Plungar, said it served burgers, chips and drinks to about 45 children on Monday afternoon.

He told the BBC the children, understood to be from Nottinghamshire and aged about 10, were in “good spirits” although tired from a two-mile walk in the village.

Mr Smeeth added the meal had been paid for by the pub, and that it was a charitable gesture he had been doing for children of Stathern Lodge Fund for about eight years.

He said police arrived at about 15:30 and arrested the man in the car park, which was “discreetly done”.

The children were taken to the village hall, and that is when parents started to arrive, Mr Smeeth added.

“[The parents] were really annoyed they couldn’t see their children,” he said.

The hall in Plungar was used as a makeshift triage centre before it was decided some of the children needed to be taken to hospital.

A 28-year-old woman who lives near the hall said: “We saw all the ambulances and police cars outside. All the kids were very guarded, they would not let anybody near it.

“Everybody was pretty stressed out. There were like four police cars, critical care teams, an ambulance, there was quite a lot. It was crazy.

“The parents were pretty stressed, they were here until probably 11pm.”

A man who also lives near the hall said: “I saw maybe one girl with her dad. She had her toy with her. They were waiting around a lot.

“It was a bit surreal I guess, a bit odd because it’s quite quiet around here.

“The parents couldn’t get any access to the kids, that was the weird thing. Just been told they weren’t allowed in basically. I felt for them.

“It was mostly confusion from what I could tell, there were a lot of cars turning up.”

Leicestershire Police said it received a report on Sunday of children feeling unwell, but did not visit the camp until Monday and had referred itself to the Independent Office for Police Conduct (IOPC).

The force said the investigation was being led by the East Midlands Special Operations Unit’s major incident team.

The IOPC confirmed it was investigating Leicestershire Police’s handling of the incident at the camp in Stathern, which is about eight miles (12.8km) north of Melton Mowbray.

The arrested man was detained on suspicion of administering poison or a noxious substance with intent to injure, aggrieve or annoy.

East Midlands Ambulance Service said it received a report of a medical emergency in Plungar at 16:00 BST on Monday.

A spokesperson said: “We sent a number of resources including four paramedics in ambulance cars, 10 crewed ambulances and responders from the air ambulance were also in attendance.”

They added nine patients were taken to the Queen’s Medical Centre in Nottingham.