The elephant herd was passing through the railway track at Subalaya near Rambha, about 45 km from here, when the Howrah-Chhenai Coromandel Express train hit them in the wee hours, said Divisional Forest Officer, Berhampur SS Mishra.
The incident could have resulted from poor visibility caused by foggy conditions in the area, forest officials said.
The train which also sustained damage, was detained on the spot, while rail services between Berhampur and Bhubaneswar were affected for some time.
It took over seven hours to restore normalcy in train services on the busy route, East Cost Railway (ECoR) sources said at Bhubaneswar.
The railway authorities from Khurda road division rushed to the spot to clear the track in coordination with the forest officials.