Battles rage in Russia as Kremlin struggles to repel surprise Ukraine incursion

The unprecedented assault entered its fourth day Friday with battles still raging and Moscow rushing reinforcements and bombing its own territory to try to contain the Ukrainian advance.

The operation has left observers struggling to track fast-moving developments on the ground — and to figure out Kyiv’s strategy in launching the attack while its forces are still struggling in several of the conflict’s longtime flashpoints.

With Ukraine tightlipped and Russian officials offering little detail on the extent of the Ukrainian advance, it’s hard to judge the scale or success of the operation beyond poring over videos, like the one showing the convoy and relying on the frenzied chatter of Russia’s influential and often-furious military bloggers.

Still, it seemed clear this was no mere headline-grabbing raid, the likes of which have been conducted by anti-Kremlin Russian militias since last year, but a carefully planned operation, military analysts have said.

“If we take a step back, it looks to me like the first time that Ukraine’s state forces have invaded Russia,” Frank Ledwidge, a former British military intelligence officer and senior lecturer in war studies at England’s University of Portsmouth, told NBC News. “That’s very significant.”

Russia’s defense ministry has boasted that Ukrainian troops had been stopped, but has yet to report pushing Kyiv’s forces back across the border.

Military command said that some 1,000 Ukrainian soldiers, backed by tanks and military vehicles, were involved in the initial attack. Federal authorities have declared a state of national emergency and thousands of people have been evacuated from Kursk amid reports of civilian casualties and destruction.

On Friday, the ministry said it was sending new reinforcements to the area. It shared videos showing columns of heavy armor headed toward Kursk, and Russian jets bombing what it said were Ukrainian troops and equipment on Russian territory.