COIMBATORE: Tormented by bedbugs, passengers in one of the air-conditioned coaches of the Jammu Tawi Express from Mangalore got off the compartment here early on Tuesday and forced railway authorities to replace the carriage.The 22 passengers in the compartment said they had been continuously bitten by bedbugs ever since the train passed Shoranur. In Coimbatore, they left the compartment with their luggage and demanded a replacement coach.The train was delayed at Coimbatore for three-and-a-half hours. The travellers shouted slogans, and the issue was resolved only after station deputy superintendent M Chandran intervened. An air-conditioned coach from another train was taken from the maintenance yard and attached to the Jammu-bound train. The compartment with bugs was disinfected and later attached to the same train.A ticket examiner said passengers had started complaining at Shoranur about the bugs. In Palakkad, they were told to wait till the train reached Coimbatore. "It was sheer luck that we were able to find an AC coach in the maintenance yard. Otherwise, things may have gone out of control," said a railway official here.The divisional office of railways in Salem blamed its Palakkad counterpart for the entire mess.