Ukraine latest news: More cracks appear on Russian state TV - and why it could 'serve a purpose' for Putin

Caution over reports of a 'nuclear train' heading to Ukraine

Reports of a "nuclear train" heading to Ukraine have spread online but these reports should be treated with caution.

This video was released online yesterday and some reports have claimed it shows a convoy of the unit responsible for transporting Russia's nuclear arsenal heading to Ukraine.

The train has been geo-located to Segiyev Posad, northeast of Moscow. This is approximately 400 miles from the Ukrainian border and it cannot be confirmed where the train is heading from the video alone.

Forbes McKenzie, former British Army Intelligence Officer and CEO of McKenzie Intelligence Services Ltd, told Sky News: "The train that has been observed has all the signatures of the 12th Main Directorate."

The 12th Main Directorate is responsible for the safe-keeping, maintenance, transportation and disposal of the country's nuclear arsenal.

"The signature equipment that is being seen is a BPM-97 armoured vehicle which we know the 12th Directorate have but it is a utility vehicle which we see throughout Russian force such as the Border Guard."

These vehicles are highlighted in this photo below of the train released on Russian social media. Analysts have noted they may feature a rare combination of weaponry, including a 30mm cannon and grenade launcher. It is unclear which units operate this version of the vehicle.

McKenzie warned further that: "At this time of year we would expect to see 12th Directorate exercising and that is not unusual. NATO units do the same thing, in fact all countries that have a nuclear capability do that."

One possible explanation is that these movements are a warning to the West. As McKenzie explains, these movements are “something that is very visible from space. It shows capability and demonstrates if Russia wanted to use tactical weapons it could do."

But reports of a possible nuclear escalation should be treated with caution: "I would strongly argue Russia don't have the opportunity to deploy nuclear weapons. It is a one-way ticket to losing, we've been told that clearly and in no uncertain terms by NATO.

"At no point have the ground forces on the Russian side been seen to be preparing to be operate in a nuclear environment.

"There are very particular units that need to be brought forward in order to deploy nuclear capabilities and troops on the ground need to be equipped with hazmat suits. We've not seen any of that take place."