Yahoo TV

STORY: Ukrainian forces achieved their biggest breakthrough in the country's south since the war began, bursting through Russian defences and advancing rapidly along the Dnipro River on Monday, threatening supply lines for thousands of Russian troops.

In a sign Ukraine is building momentum on two fronts, 1980 miles to the northeast Reuters saw columns of Ukrainian troop vehicles heading to reinforce rail hub Lyman, retaken at the weekend and a staging post to press into the Donbas region.

Kyiv gave little information about the gains in the south, but Russian sources acknowledged that Ukrainian troops had advanced along the river's west bank, recapturing a number of villages along the way.

The advance is targeting supply lines for as many as 25,000 Russian troops on the west bank of the Dnipro. Ukraine has already destroyed the main bridges, forcing Russian forces to use makeshift crossings. A substantial advance down river could cut them off entirely.