Ranchi, Oct 12 : Maoists set on fire four vehicles engaged in railway line construction work in Shahpur-Hesa Kudar Village in Hazaribagh District in the wee hours of Thursday. The Maoists also left leaflets at the spot that falls under Katkamsandi police station, in which they have taken responsibility for the arson. It is suspected that the Maoists carried out the attack in a bid to intimidate and extort money from the construction company. About a dozen Maoists reportedly reached the construction site of the Kathautia-Tori Chandwa railway line at 3 a.m. and they burnt two Hyva trucks, a payloader and a pickup vehicle that belonged to the railway company, sources said. Police reached the spot and are investigating the matter. They are also conducting a search operation against the Maoists. This is the third attack by Maoists on a railway construction site in Jharkhand in the last one-and-a-half months. On September 25, Maoists had attacked the railway construction site at Mccluskieganj in Ranchi district and set on fire three vehicles and a generator engaged in construction work. Similarly, on September 1, the banned organisation PLFI had attacked the railway construction site near Kanaroan railway station in Simdega district and set a Poclain machine on fire. On August 23, Maoists had also attacked a road construction site in Palamu and torched eight vehicles. The Jharkhand Rail Infrastructure Development Corporation Limited (JRIDCL) had recently written a letter to the state's Home Department requesting for security in view of the frequent attacks on construction sites because of which many railway projects were being disrupted and delayed. /IANS