More than 250 train services have been delayed or cancelled due to bomb alerts in the North this year, it emerged today.
Most incidents involve hoax devices but one real bomb has been discovered.
Many happened on the line between Belfast and the Border.
Dissident republicans have been blamed for many of the incidents, although community representatives in Lurgan claim young people are behind a sporadic campaign.
The Belfast to Dublin line is one of Ireland's main commercial transport links and bomb alerts have been blamed for causing widespread disruption to business and holiday users on the route. Services are also used by thousands of commuters in Dundalk and Drogheda, Co Louth.
A Northern Ireland Railways spokeswoman appealed for the attacks to stop and said they caused severe inconvenience to passengers and staff.
"We would appeal to parents, teachers and community representatives to continue to highlight the dangers of trespassing on or near railway lines to all those in their community including children and young people," a spokeswoman said.
She added hoax alerts caused similar levels of disruption as live devices with sections of the railway closed and a heightened security force presence. There is a STG£1,000 reward for people witnessing trespass on rail lines who give evidence in court and there has been a heavy advertising campaign to discourage potential offenders.