Thiruvananthapuram, Aug 28 (IANS): The railways are short-changing Kerala while earning handsome revenue from the state, resulting in incidents like Sunday's derailment, PWD Minister G. Sudhakaran said.

In a letter to Railway Minister Suresh Prabhu, Sudhakaran expressed concern over the derailment of the Thiruvananthapuram-Mangalore Express in Kerala and said the state had been treated unfairly in provision of infrastructure.

"Kerala provides the biggest revenue to Southern Railway. But when it comes to railway infrastructure, Kerala's need is always ignored," Sudhakaran wrote.

"The quality of the coaches on trains in Kerala is the worst. Then there are no timely repairs and maintenance of the tracks in the state. All this could be reasons for frequent derailment," the minister said.

He sought Prabhu's intervention to see that the situation that caused the derailment was remedied and normal rail traffic was restored at the earliest.

The railways should also investigate what caused the derailment, he said.

The derailment resulted in cancellation of a number of trains. Some trains were also diverted and many of the services were terminated midway.

Complete normalisation of rail traffic could well happen only by Monday, Southern Railway officials said.