Train Derails in Iowa, Mass Evacuations Underway as Fire Grows

Mass evacuations are currently underway in northwest Iowa -- where a train derailment has sent its cars bursting into flames ... and hazmat crews storming in.

The accident appears to have occurred just a short time ago near the city of Sibley, where black smoke has been billowing for several minutes now. Somebody nearby captured footage of the crash, and you can see spouts of flames coming up from behind a building.

Several different rescue crews are en route, as there are concerns the train might've been carrying flammable liquid ... which would explain the fire that's growing on site. Word is that authorities are clearing the area within a 5-mile radius ... so a massive hazard's unfolding.

Another person captured a photo from further away showing the damage, and it appears a massive pile-up occurred during the derailment. Unclear what might've caused it to get off the tracks in such violent fashion, but this isn't the first wreck like this, this week.

A Union Pacific train derailed in south Minnesota Saturday, with a huge pile-up of cars there as well, with upwards of 28 cars falling off the track. And even earlier in the week, there was a report of yet another derailment in Missouri -- where six cars came loose and spilled into a main road.

Reports of any injuries or fatalities from this latest disaster in Iowa haven't surfaced -- but we're monitoring for updates.