British Transport Police say it happened overnight Monday (2nd July) into Tuesday (3rd July)
Images of 4 large tags spreading the length of at least 3 windows have now been released.
BTP Devon & Cornwall tweeted to say those responsible risked their lives trespassing on the railway and their actions could land them with an unlimited fine or up to 10 years in prison.
They're now looking for those who caused the damage.
Last night of the Christmas Proms - REVIEW
Bournemouth Symphony Orchestra at the Great Hall
Christmas snow possible on Dartmoor
That's despite no white-Christmas predicted
Car thug sought
This man may be able to help enquiries
Young teenager stabbed in Plymouth
No arrests made
Stalking suspect sought
Call 999 if you see Conor Braund, 30,
Plymouth will not delay local elections
Exeter pressed for a decision
