The build-up of Russian forces close to the Ukrainian border continues apace, with everything from submarines and amphibious landing ships in the Black Sea to short-range ballistic missiles, tanks and howitzers around Ukraine’s northeastern edges.

CNN has geolocated and authenticated social media videos of these movements – though there are likely many more that are not being observed.

Some of the videos come from official sources; most are from TikTok or YouTube. They are being analyzed by online observers and often complement satellite imagery.

There’s plenty of other evidence of the military build-up in the Belgorod region too.

CNN geolocated these videos at the village of Sereteno, about 15 miles (24 kilometers) from the border. They were uploaded on Sunday and show tanks moving through the area.

Helicopters near Belgorod

In the last couple of days, more social media videos have featured the arrival of helicopters near the Ukrainian border. They could offer important protection for ground troops in the event of an offensive.

The Russian build-up includes tanks, infantry fighting vehicles known as BMPs and self-propelled artillery.

A lot of the hardware is traveling south from the city of Kursk.

Missiles and artillery support

Michael Kofman, Russia analyst at CNA, a nonprofit organization based in Virginia, notes that units in Kursk (such as the 6th Combined Arms Army) “appear to be moving up to Belgorod with district level artillery support.” He says the 1st Guards Tank Army has started to move too – “presumably to a final staging area.”

Of particular concern is the movement of convoys of Iskander-M short-range ballistic missiles, which seems to have picked up in the last few weeks in various parts of western Russia.

If a conflict began, these would likely be used to attack fixed Ukrainian positions -- such as command and control sites. They have a range of up to 250 miles (402 km) and have been spotted in recent satellite imagery.

Rocket launchers near border

Russian and Belarusian troops began sizeable joint exercises last week near the Polish border, but some Russian forces are on the move many miles from where the exercises are taking place and have taken up positions close to where the borders of Ukraine, Russia and Belarus meet.

CNN geolocated this convoy, which includes multiple rocket launchers, to a spot about 15 miles (24 kilometers) north of the Ukrainian border.

Russian weaponry – and ships – continue to close in on the Ukrainian border. Sites where equipment had been pre-positioned more than 100 miles (161 kilometers) from the border have been progressively emptied as units have moved forward.

There are Russian units within a few miles of Ukraine all the way from the Sea of Azov, along the Ukrainian border and into Belarus.

“Russia’s current military buildup near Ukraine is unprecedented,” tweeted Rob Lee, from the Department of War Studies at King’s College London. “This is not like previous war scares or the buildup in the spring [of 2021]. The amount of Russian aerial, ground, and naval military power near Ukraine now is quantifiably far greater.”

While the equipment appears to have been assembled, where it’s moved to next – and when – remains unknown. (CNN)