Over half a dozen passenger trains under South Eastern Railway's Chakradharpur division will remain cancelled from December 22 to 24 due to elephant movement near tracks. Officials said a herd was spotted between the Chakradharpur (Jharkhand's Singhbhum) - Jharsuguda (Odisha) section, particularly near Bondamunda at night. Trains are being slowed to ensure safety, leading to delays, official said.