Army bomb disposal experts have carried out a controlled explosion on a bomb found on the railway line between Lisburn and Moira.
The Army carried out a controlled explosion on the device
The security alert has now ended and remains of the device have been taken away for scientific examination.
The Moira Road, which was closed during searches, has since re-opened.
Trains between Lisburn and Portadown are cancelled on Tuesday and Wednesday because of what Translink called "a perceived risk in the Lurgan area".
In a statement, Northern Ireland Railways said the safety of staff and passengers was a top priority.
A bus service is running between the towns instead.
In previous years, trains have been targeted at this time of year while going through Lurgan where the line runs past the mainly nationalist Kilwilkie housing estate.