A COLLEGE in Abingdon has said a series of loud bangs heard near its campus moments before students were evacuated were a 'coincidence'. 

The science block at the Northcourt Road campus of Abingdon and Witney College was evacuated at around 1pm today after a student experiment went wrong.

Fire crews were called to the scene with witnesses reporting a series of 'loud bangs' coming from the campus.

However, the college has said the site was evacuated after a 'small amount of harmless gas' released during the experiment had set off the smoke alarms, blaming the loud noises on a passing car. 

One man who lives opposite the college on Northcourt Road said he heard what sounded like several explosions at about lunchtime and looked out his window to see pupils assembling outside the buildings.

He told the Oxford Mail: “There was a series of loud bangs like an exhaust backfiring but louder - it was really loud.

“I'm presuming they had to evacuate, the pupils congregated out front.”

Speaking shortly after 3pm he said all the students seemed to have gone back inside.

Principal of Abingdon and Witney College Di Batchelor said: "On Friday November 9 at approximately 1pm at our Abingdon campus, a smoke alarm was set off in one of our science laboratories.

"A small amount of harmless gas was released during an experiment which triggered the smoke alarm.

"As a precaution the Oxfordshire Fire Service was asked to attend, and the campus was evacuated.

"Nobody was hurt, and there was no damage to any property.

"We apologise for any inconvenience caused to our students, staff and the local community."

A spokesman for the college later confirmed the loud bangs were caused from 'the exhaust of a passing car' and were 'just a coincidence'.

A spokesman for Oxfordshire Fire and Rescue service said three fire engines were sent to the college at around 12.56pm and stayed at the site for around an hour.

The spokesman confirmed there had been a small ‘chemical reaction’ in a fume cupboard, with crews venting the area.

No-one was injured.