Equipment went up in flames at a North East sports stadium.
Hurdles and crash mats were reportedly set alight on the astro turf at Gateshead Stadium as athletes trained.
Firefighters were called to blaze at about 6.45pm last night.
Firefighter David Bell told reporters: “We were called to what we thought was a wheelie bin fire, and when arrived we found the corner of the astro turf pitch was on fire.
“The police were already in attendance, away trying to catch whoever may have done it.
“Someone appeared to have pulled four of the crash mats out, as well and some of the hurdles, and spread them out on the ground. By the time we arrived, the mats had burned through, and melted onto the astro, and the hurdles were still alight.
“We gave it all a good soaking and it was out within 10 minutes.”