A loud explosion could be heard for miles when a Second World War bomb found in Exeter was detonated.

Devon and Cornwall Police were alerted after the device was discovered on a building site on private land to the west of the University of Exeter campus at about 9.20am on Friday.

Initially, a 100-metre cordon was erected, but this was extended to 400 metres on Saturday at the request of the Royal Navy bomb disposal team.

Around 2,600 properties in the vicinity of Glenthorne Road, including 1,400 university students, were evacuated on Friday and Saturday.

Police warned that a “loud bang” was expected when the bomb was detonated on Saturday evening, but said there was no cause for alarm as the cordon meant there were no health risks to anyone beyond its perimeter.

Speaking ahead of the detonation, a force spokesman said pets and small children should be kept indoors and people should not gather outside.

“Personnel from the Army’s Royal Logistics Corps took over from Royal Navy bomb disposal experts this morning in preparation for the controlled detonation of the device,” he said.

“Both teams have been responsible for erecting a walled mitigation structure. This afternoon, trenches have also been created to prevent ground shock.

“After the detonation, assessments will be conducted by various utility companies prior to residents returning. It is anticipated that the majority of residents will be able to return home this evening.”

However, Exeter University asked students not to return to their residences on Saturday as safety assessments needed to be conducted.

One student, Fran Henderson, 18, was told to pack at 7pm on Friday before being taken to a hotel outside of Exeter at 1am on Saturday.

The politics, philosophy and economics student told the PA news agency that she had been informed it was “most likely” that she would be able to return to her student residence at 12pm on Sunday.

“The site is about 120 metres away from our accommodation,” Ms Henderson said.

Police previously said that the majority of residents in private homes were staying with family and friends.

Devon County Council confirmed that visiting friends and family was allowed in such circumstances, despite Covid-19 restrictions.

Road closures were put in place between Cowley Bride and Exe Bridges, with diversions in place and motorists asked to avoid the area.