TasRail chief executive Damien White said that recent warm weather appeared to have encouraged a series of potentially fatal bridge-jumping incidents, reported by highly concerned TasRail drivers.

``Children and teenagers have been jumping off bridges at Heybridge, Deloraine and Longford,'' Mr White said.

``One incident saw children and teens jumping off the Longford rail bridge into the water on the weekend, causing the vigilant driver to stop the train and block the main road crossing until he could be certain they were gone.

``This put children, the driver and vehicles at risk.

``Members of the public phoned TasRail to complain the road was blocked.''

Mr White said if such high-risk behaviour continued, it would only be a matter of time before tragedy struck.

Longford Senior Sergeant Chris Parr said he was alarmed at such reports. ``River levels can vary at times and this may expose hidden objects leading to potentially fatal consequences,'' Senior Sergeant Parr said.

``Trespassing on railway infrastructure is an offence and individuals may be prosecuted. Police will be working with TasRail to prevent this type of high-risk behaviour.''

Senior Sergeant Parr encouraged people to report these incidents to police by calling 131 444.

Northern Midlands Mayor Kim Polley said the council was equally concerned.

``It's extremely dangerous and just totally foolhardy,'' she said.

``We would like to support TasRail and police to ensure that this discontinues immediately.''

Cr Polley reiterated the dangers with floodwaters bringing hidden debris.

``Young people often think they are bulletproof,'' she said.

``There will be there a fatality there one day.''

Mr White said one of the worst examples in recent weeks occurred at Burnie on Tuesday.

The train driver reported that a man and three young children, all under the age of 10, were running across the pedestrian crossing near the Burnie wharf, along the foreshore, while the train was only two engine lengths from the crossing.

Mr White said that the driver sounded his warning whistle and flashed his lights repeatedly, but the adult pedestrian responded by giving the driver ``the finger'' while the children watched.

He said increasingly stupid acts put lives at risk, were incredibly dangerous and were clearly unacceptable. ``It puts immense stress on our drivers who are everyday Tasmanians coming in to do their jobs safely,'' Mr White said.

``A near-miss, particularly involving children, can traumatise a driver and have a devastating effect on them and their families if they are unable to work due to stress.''

Mr White urged people to heed the rail safety message and consider past tragedies and their wide-ranging impact.

Email: ctang@examiner.com.au