A 15-year-old boy has been arrested following an incident at the Armagh campus of the Southern Regional College which saw nine students rushed to hospital.
The teenager was arrested on suspicion of drugs-related offences.
Emergency services were rushed to the scene on Friday shortly before 1pm after the students fell ill.
SRC Chief Executive, Brian Doran, told the BBC that those affected were pupils of Markethill High School who attend the college one day a week on vocational programmes.
They have all made a full recovery following assessment at Craigavon Area Hospital.
“They were taken to hospital as a result of staff acting when one or more students fell ill,” said Mr Doran.
“The college liaised with the school. The school had staff on premises. We worked with the school staff to inform parents, and the emergency services were on hand fairly quickly.
“The concern was to get the students medical treatment as quickly as possibly, which thankfully they did.”
He added: “We’ll carry on our own investigations with the school early next week to try and ascertain what was the nature of the incident.”