A train derailed Sunday morning in the U.S. state of Montana and local authorities claimed there was no risk to public safety.Montana Rail Link (MRL), which operates an over 1,400-km track linking Montana and its neighboring state of Washington, said in a statement that about 20 to 25 cars of a freight train derailed into the Clark Fork River in Sanders County at about 9:20 a.m. local time (0320 GMT).Investigation was underway to determine the cause of the derailment, said the company, adding that its personnel were on the scene with first responders.Pictures posted online showed that debris was strewn below some of the wrecked railcars, and at least a dozen railcars were involved.There was no immediate report of casualty so far.The derailment came after several such incidents in different parts of America in recent weeks, with one in Ohio causing the release of tons of toxic chemicals that triggered protests among local residents and alarmed the whole nation.A train derailed Sunday morning in the U.S. state of Montana and local authorities claimed there was no risk to public safety.Montana Rail Link (MRL), which operates an over 1,400-km track linking Montana and its neighboring state of Washington, said in a statement that about 20 to 25 cars of a freight train derailed into the Clark Fork River in Sanders County at about 9:20 a.m. local time (0320 GMT).Investigation was underway to determine the cause of the derailment, said the company, adding that its personnel were on the scene with first responders.Pictures posted online showed that debris was strewn below some of the wrecked railcars, and at least a dozen railcars were involved.There was no immediate report of casualty so far.The derailment came after several such incidents in different parts of America in recent weeks, with one in Ohio causing the release of tons of toxic chemicals that triggered protests among local residents and alarmed the whole nation.