There is a big crater somewhere in the Pinezhsky District of Arkhangelsk oblast. That's about 200 km downrange from the Plesetsk test site. According to eyewitness accounts published in the local press, the crater appeared after an explosion that was heard around noon on August 25, 2016. This is how the area looks like:

It's not Tunguska, of course, but the explosion seems to have been very powerful. The crater is also quite big. There are actually two craters, and the size of the larger one is more than 100 meters. In fact, it can be seen from space:

Since the explosion point is not that far from Plesetsk, it was natural to suggest that it was some kind of a launch failure. A local civil defense official confirmed that it was in fact "a stage of a missile/rocket launched from the Plesetsk cosmodrome." Given that there was no attempt to cordon off the area, it was a relatively harmless solid-propellant motor, which very much rules out a space launch (or such exotic versions as an early test of a Sarmat missile). Other intriguing possibilities have been mentioned - a Nudol ASAT test for example (which in fact failed once in 2015). However, the impact point is so close to the path from Plesetsk to Kura, there is little doubt it was a launch of an ICBM.

Indeed, I have it on good authority that the missile that failed in the August 25 launch was RS-24 Yars. No official confirmation yet, but I hope we will hear more about the test in the coming days. One thing that would be interesting to learn is the failure mode - as far as I can tell, it is somewhat unusual for a missile to fail and land 200 km downrange. To land there, the missile must have failed fairly early in flight, in which case it should have been destroyed by range safety. Apparently it wasn't.

In any event, a failure of RS-24 Yars in what appears to be a routine test cannot be a good news for the Strategic Rocket Forces. The Topol-M/Yars missile has been a very reliable machine so far and I don't think it ever failed in a flight test before. It's just one failed test, of course, but it will raise questions about reliability of the system that is on its way to becoming the main ICBM in the Russian arsenal.

UPDATE 8/17/17: It was indeed a Yars launch, but not quite - the book "Northern Spaceport of Russia, vol. 3 (Северный космодром России. т. III) lists this test as a "first test launch of the Yars-M ICBM":