A passenger train hit and killed three young elephants in eastern Sri Lanka, officials said Sunday, weeks after two calves and their pregnant mother were fatally struck in the same region.The Colombo-bound train with 600 passengers hit the herd near the village of Welikanda, 260 kilometres (162 miles) east of the capital on Saturday night.The incident came less than three weeks after a similar crash involving a fuel train in the same region.The three elephants, part of a larger herd, were crossing the railway track at dawn in jungle near Habarana, 180 kilometres (110 miles) northeast of Colombo, when they were hit and killed late last month.The latest accident came even as the authorities investigated the previous crash to determine if the train driver had followed standard procedures while operating in jungle areas with elephant populations.Drivers are usually expected to move slowly and sound the horn continuously to warn any wild animals on the track.