KUALA LUMPUR, Dec 4 — RapidKL is advising commuters to avoid its Kelana Jaya LRT line that is facing massive congestion and slowdowns caused by an earlier derailed maintenance car.

The light rail operator urged users to seek alternative forms of transportation as it did not have a firm timetable for the end of the disruption that has completely halted service from KLCC and Gombak.

"KJ Line Update: Our service is experiencing a major delay due to a derailed maintenance car between Jelatek and Dato’ Keramat.

"Customers are highly advised to seek alternative transport. Updates to follow,” it announced on Twitter.

Service elsewhere was intermittent, forcing RapidKL to deploy shuttle buses to cope.

It said users will get full refunds of their fares.

Touch ‘n’ Go users must obtain a refund voucher from the customer service windows before tapping out.