It comes 24 hours after workmen discovered a suspicious object close to Malone Bridge on the Lurgan side of Bells Bridge. The alert has caused disruption to the rail timetable.

The line between Lisburn and Portadown is closed. Army technical experts are due to examine part of the line.

SDLP Assembly member Dolores Kelly claimed dissident republicans were training young people to leave devices.

"Local people reported to us seeing young people being almost trained in paramilitary fashion to leave the device and wearing balaclavas," she said.

"So, it seems as if there is an element of recruitment amongst dissident republicans training young people, or at least corrupting their lies, and disrupting the lives of everybody else around them."

She said hoax devices were often left as a means of luring security forces into the area, to be attacked.

Ms Kelly also condemned the disruption caused by such incidents to every day life.

"There is not easy transport access outside of Lurgan other than the train and it is widely used," she said.

The police have advised people to avoid the area while the alert continues.