Children at a school near Bristol which was evacuated in a suspected chemical incident are expected to return to classes later.

Emergency services were called to The Manor C of E Primary School in Coalpit Heath at 13:15 BST on Monday.

An investigation into what caused pupils to become ill is continuing.

A message on the school's website said there was no problem with the building and it would be "open as usual" on Tuesday.

Six children were sent home and 34 were treated for nausea and headaches on Monday.

Dr Phil Cowburn, from the Air Support Unit which attended the scene, said that although the children had potentially worrying symptoms such as feeling queasy and faint, nothing serious was identified.

"We checked for any signs of chemical exposure, any significant exposure to carbon monoxide which could cause these children to be unwell," he said.

"We are happy that they had no signs of anything worrying."

All children were allowed home with their parents.

Avon Fire and Rescue Service had received a call just after 13:30 BST to say six children at the school were drifting in and out of consciousness.

Station manager Steve Imrie said an investigation was under way to determine the cause of the sickness.

"It's been a fairly large, multi-agency event with fire ambulance, police and local authority working together," he said.

"At this stage we still can't put our finger on what the actual cause was."

The school has advised parents to keep their children at home if they are still feeling unwell.