Update (0045 EST): First responders now reporting 5/7 cars of a passenger train derailed on the Tabas axis of the route. 16 now reported critically injured.

Update (0014 EST): Iranian Roads and Urban Development Deputy Minister Mousavi says train derailed after striking excavator on the rail line. At least ten helicopters have been dispatched to these scene of three rail cars derailed. 12 are confirmed to be critically wounded.

Social media users in Iran are reporting that a train derailment between Yazd and Mashhad, Iran has left at least 10 dead and at least 50 wounded.

Mr. Rezaei, leader of the Red Crescent Society for Southern Khorosan, is reporting that at least six Red Crescent teams are on site assisting with the casualties. At least three train cars filled with people have overturned off the tracks.

This story is developing.