Goa-bound Rajdhani Express from Hazrat Nizamuddin derailed inside a tunnel in Ratnagiri district of Maharashtra early on Saturday, but there was no report of injury to any passenger, an official said.

The train - 02414 - was going to Madgaon in Goa when it derailed inside Karbude tunnel, approximately 325 kms from Mumbai, around 4.15 am, a spokesperson of the Konkan Railway, which operates the route, said.

A boulder had fallen on the tracks, which led to the derailment, he said.

"The front wheel of the locomotive of Rajdhani superfast train derailed in Karbude tunnel located between Ukshi and Bhoke stations in Ratnagiri region of the Konkan Railway," the official said.

A rail maintenance vehicle (RMV) has reached the site and an accident relief medical van (ARMV) having re-railing equipment has left for the site from Ratnagiri for the restoration work.

"Konkan Railway officials have also rushed to the site to clear the line," he said. The Konkan Railway operates 756 km-long route between Roha near Mumbai and Thokur near Mangalore. This route, which is spread across three states - Maharashtra, Goa and Karnataka - is one of the challenging terrains with many rivers, gorges and mountains.