Train traffic on the Chennai-Howrah main line was affected following the derailment of goods train bogie at the Rajamahendravaram railway yard early on Wednesday.
Consequently, the South Central Railway cancelled nine important trains on the Vijayawada-Visakhapatnam section for the day.
While three more trains were cancelled partially between different stations, another was rescheduled by two hours, according to SCR Vijayawada division Public Relations Officer Nusrat M Mandrupkar.
The derailment happened closer to the Rajamahendravaram railway station on the down main line, leaving only one line open on the busy Chennai-Howrah route that sees the movement of hundreds of trains.
The cause of the accident was not immediately established, even as a team of officials from Vijayawada rushed to the spot to carry out restoration works, official sources said.
The line is expected to be restored by the afternoon after the derailed bogie is cleared.