Three passengers were killed and 21 others injured when 14 coaches of the Nagercoil-Howrah express derailed near Duwada village in Visakhapatnam district late Monday night, disrupting rail services in the region.

The passengers killed in the mishap have been identified as M Prasad Rao, Birendra Jena and Sisir Jena.           

East Coast Railways Chief Public Relations Officer B K Mishra said in Bhubaneshwar that 21 passengers were injured in the mishap, seven of them seriously.

"There might have been more injuries, mostly minor in nature," Mishra said.

The injured persons had been shifted to the King George Hospital and railway hospital while a relief train has reached the spot with equipment, Mishra said.

The derailment occurred at a steep curve near Gopalpatnam, he said, adding the cause of the mishap was under investigation.

A control room has been set up at Visakhapatnam to provide assistance and inquiries can be made on 0891-2575083.

Rail services have been disrupted in the Visakhapatnam section following the derailment with number of passenger and express trains either diverted or cancelled on Tuesday.

South Central Railway, Vijayawada Division cancelled several express and passenger trains including Vijayawada-Visakhapatnam Ratnachal Express, Visakhapatnam-Tenali

Janmabhoomi Express, Guntur-Visakhapatnam Simhadri Express, Rayagada-Vijayawada Passenger, Visakhapatnam-Vijayawada passenger and Visakhapatnam-Machlipatnam passenger.

Rail traffic is expected to be restored by Tuesday night, the officials added.

The mishap has also affected railway traffic on the Howrah-Chennai trunk line as the down line has been obstructed.

Mishra said traffic has been reopened on the up line though several trains were running behind schedule. Many trains on the route had been stopped at various stations, he said.