The incident happened on Tuesday evening in Jedlanka, in Poland’s eastern Lubelskie province, when two freight trains travelling in opposite directions hit the blocks, officials said.
The concrete came from the remains of a demolished railway platform at a nearby station.
The blocks damaged the snowploughs at the front of the locomotives, but neither train derailed and neither driver was injured.
Rail traffic in the area was suspended for several hours.
Police determined that the boy had pushed concrete fragments from an embankment onto the tracks. He also placed several stones on the tracks.
The boy was questioned in the presence of a parent and admitted to causing the incident, state news agency PAP reported.
The case will now go before a family and juvenile court in the town of Łuków, which will examine the circumstances and determine whether his behaviour is a sign of demoralisation and whether educational measures should be used, officials said.
(sp/gs)
Source: PAP