NEW : It 's unclear how much of a role Russia played , U.S. intelligence says . Comment: Ukrainian President Petro Poroshenko rejected that in an exclusive interview with CNN , saying that all Ukrainian aircraft were on the ground at the time . Ukraine opens criminal cases against Russian defense minister and businessman . Dutch official : At least 200 bodies were on the train ; more could be at crash site .
NEW : It 's unclear how much of a role Russia played , U.S. intelligence says . Comment: Ukraine opens criminal cases against Russian defense minister and businessman . Dutch official : At least 200 bodies were on the train ; more could be at crash site .