THE tragic deaths of two teenagers on a railway line have led police to pledge tough action against anyone involved with underage drinking, if it is found the boys had been drinking alcohol before they died.

Friends who were with Stuart Adams, 15, and Lee Mullis, 14, in Darlington on Friday night minutes before they were hit by the 8.30pm Manchester Airport to Newcastle service, said the group had been drinking.

The boys, who went to Longfield School, were killed instantly as they played on the track on the East Coast Main Line, near the Five Arches bridge.

Police said they could not confirm that alcohol played any part in the deaths, and would not comment until they received laboratory reports, but pledged a major crackdown on underage drinking if a link was shown. The Streetsafe unit has been created recently in Darlington to target the hardcore of youngsters who cause trouble across the town, and to tackle the problems of alcohol and anti-social behaviour.

The unit is already being hailed as a success, and police promise that their uncompromising approach to teenage drinking will continue.

Acting Inspector Alison Jackson, of Durham Police, said it had not yet been established if the youngsters had been drinking.

"At this stage we are not sure if the two youths had been drinking, and will not be until we get the results of the toxicology tests," she said.

"We will also be speaking to witnesses about the night's events. We are dealing with it in the appropriate way, and will not speculate. However, if it comes to light that drink did play a part, then it will become a main priority.

"If alcohol has been a contributing factor, then it is something we will be looking at, and we will be stepping up our actions and trying to make sure that something like this does not happen again.

"Underage drinking has always been a concern, and these events have really brought it to the forefront.

"Incidents like this, and all the speculation about drink, highlight the fact that when people are drinking it can cloud your judgment."

Acting Insp Jackson said that underage drinking was a difficult problem to tackle, but the StreetSafe team was doing well. "The unit has done a really good job, even though it is in its infancy."