Four elephant calves died when they were hit by a passenger train in Sri Lanka on Wednesday, Police said.The baby elephants were walking on a newly constructed railway line in Vavuniya district when they were hit by the Colombo bound Thaleimannar Express train, Xinhua news agency reported."The Wildlife Department together with the Sri Lanka Railways has been trying to identify paths which wild animals usually frequent. Along these routes trains usually reduce their speed and are very cautious. Wednesday's accident took place in an area where there have been no wild life movements," a railway official said.Elephants are considered sacred in Sri Lanka and are legally protected. However, many are killed every year, mostly by angry villagers and farmers, when they trespass into human habitations.The accident is said to be one of Sri Lanka's worst involving wild animals.