The coaches of Nagercoil-Howrah Gurudev Express derailed on Monday around 11 pm between Duvvada and Gopalapatnam railway stations of East Coast Railways near Visakhapatnam.
The injured have been admitted to King George Hospital in Visakhapatnam, where the condition of four people is stated to be critical.
The South Central Railway, Vijayawada Division cancelled several express and passenger trains including the 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. East Coast Railway CPRO BK 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.