The RCMP say a suspect has been arrested after a student was threatened at a high school in Sussex, N.B.

The student told his principal he was behind Sussex Regional High School when he was approached and threatened by a student and an unidentified man armed with what appeared to be a gun.

Police responded to the school around 10:45 a.m. Friday.

Both the high school and nearby middle school were placed on lockdown until noon as a precaution.

At first, some students thought the incident was a drill, but quickly realized the seriousness of the situation.

"We realized how long it was taking and we had our cellphones and we were contacting students from other schools and they told us they were on lockdown too and we realized it wasn't a joke," says student Katrina Belding.

Police located and arrested one of the suspects Friday afternoon and regular classes resumed.

Some parents opted to bring their children home for the day.

The second suspect has yet to be located.

There is no word on charges at this time. The incident remains under investigation.