DCI detectives and KWS rangers on Thursday night arrested three men found vandalising the metre gauge railway in Mtito Andei, Taita Taveta county.
The three were found loading cable wires,nuts and rollers into into a lorry.
The suspects: Bernard Mwadime, Paul Wambua and Nelson Kenneth as well as the lorry driver Andi Ibrahim were taken into police custody and will be arraigned in court once police conclude their investigations.
Last year, President Uhuru Kenyatta warned that railway vandals risked being hanged if found guilty.
Uhuru said destruction of the railway line amounted to economic sabotage, a capital offence whose punishment in Kenya is hanging.