A toy train of the Darjeeling Himalayan Railway (DHR) derailed near Darjeeling town on Thursday, making it the fourth such incident in the past 20 days.

Since December 15, toy trains of the DHR, which has been recognised as a world heritage property by Unesco, have derailed in different locations across the hills. Although no casualty has been reported in any of the incidents, frequent derailments have posed a question as to whether the tracks and the rolling stock of the heritage railway are being properly maintained.

A toy train, which comprised a steam loco and two coaches and was engaged for a joy ride, went off the tracks at Kakjhor near Darjeeling town around 2pm on Thursday. The train was heading towards Ghoom.

“As the area is near Darjeeling station, the staff and technical experts rushed to the spot. They could bring the loco back to the tracks in one hour, after which the train left for Ghoom. There were 59 passengers on board and all of them were safe,” said a source in the DHR.

The joy ride — a return journey from Darjeeling to Ghoom — is the most popular toy train service among tourists in the hills. Hundreds of tourists avail themselves of the rides every day.

Sources said toy trains for joy rides had derailed on December 15 and January 1. The regular service between Darjeeling and New Jalpaiguri suffered on December 20 as a steam loco went off the tracks near Mahanadi. It was later taken to the DHR’s workshop in Tindharia for maintenance work.

The back-to-back derailments prompted railway officials to initiate an inquiry.

Sabyasachi De, the chief public relations officer of the Northeast Frontier Railway, said: “Our technical experts are conducting a probe to find out the reasons for derailments. We will act on a report to be submitted by them."

Stakeholders of the tourism industry expressed their concern over the derailments.

“If toy trains derail frequently, it would discourage tourists from taking rides. The incidents can affect the inflow of tourists. The railways should ensure that the tracks, coaches and locos are properly maintained,” said Samrat Sanyal, the general secretary of the Himalayan Hospitality & Tourism Development Network.