An attempt to sabotage a popular biking trail in Belfast could have caused a death, it has been warned.
A full-scale search operation was launched yesterday after a deadly trap was set for mountain bikers on Belfast's Cave Hill.
Fishing wire was found strung across two trees at around head height on one of the routes around Belfast Castle.
The sinister incident comes just weeks after wool was tied at head height between trees at a trail in the Mournes, raising fears of a concerted attempt to target bikers.
With its twisting single track drops and downhill trails through the trees, the area around Belfast Castle has become a popular destination for thrill seekers on two wheels.
A number of popular mountain bike blogs recommend the location as a must.
However, yesterday Belfast City Council was forced to mobilise every available park warden to comb the mountainside for more traps after the fishing wire discovery.
They worked until the end of their shifts to ensure the safety of those using the hill and continued their searches on Wednesday.
A spokesman urged caution and for anyone who may spot something suspicious in the area to contact the council.
The discovery was also reported to the police and to an informal group of mountain bikers who regularly pass about information about such incidents as they occur.
James Cunningham, who is a member of the group, said: "Over the past weeks and months we have noticed an increase in obstacles being deliberately put in the way on the trails. Things like logs or rocks. But this is even more frightening," the 28-year-old civil servant said.
James would regularly ride the trails around the area on his mountain bike. "It can be sore enough when you've just yourself to blame for coming off, but this could really injure or worse. Nothing can justify it.
"People need to realise the harm this could do, this could kill."
Cormac Hamill of the Cave Hill Conservation Campaign said the group works with cyclists who use the hill to foster positive relationships. He was angered to hear of the trap laid out for those using the hill on their bikes.
He said: "This is utterly reprehensible. The pudding head responsible has no idea of the potential damage they could cause.
"We work with cyclists on building a respectful atmosphere on the hill - it's free for all to use. In the main, we all get on well, there can be the odd frustration, but everyone tries to respect each other when they use the paths.
"Then there are those on the outer fringe - both cyclists and walkers - who take it to the extremes. But this is just beyond understanding."
PSNI Inspector Roy Burnside said: "This was an unbelievably dangerous thing to do. Whoever was responsible could have caused serious injury, or worse, to anyone using the track had this wire not been found by a member of the public, who I commend for his vigilance.
"This area is open to the public, and I would appeal to anyone who saw any suspicious activity in the area at any time, or who can provide any information as to whoever carried out this reckless act, to contact police on 101 quoting reference 645 of July 19.
"Alternatively, information can be given anonymously through Crimestoppers on 0800 555 111."
The discovery comes just weeks after traps were laid for mountain bikers during an event on the Mourne mountains.
Glyn O'Brien from Newry, who ran the Vitus First Tracks Enduro Cup at Kilbroney Park in Rostrevor, blamed disgruntled hill walkers for setting the traps.