Ukraine is engaged in a desperate fight to hold back the Russian onslaught.

Russian forces captured the longtime Ukrainian stronghold of Avdiivka before dawn on Saturday, Moscow’s first major battlefield gain since it took Bakhmut last May.

But across the entire 600-mile long front, Ukraine is short on ammunition without renewed American military assistance, and it is struggling to replenish its own depleted forces after two years of brutal fighting.

Russia’s assault has split into five major lines of attack, spanning towns and cities across much of the front in eastern and southern Ukraine. Here is the status of Russia’s offensive in five critical battles:

1. Avdiivka

Russia captured a longtime Ukrainian stronghold.

The now-destroyed city of Avdiivka covers only some 12 square miles. But for the better part of a decade it carved a bulge in the front line that undermined critical Russian logistical operations. It sits only a few miles from the city of Donetsk, which Russia has occupied since 2014.

In recent weeks, Russian forces have breached a critical supply line and threatened to encircle Ukrainian soldiers. Oleksandr Tarnavskyi, the head of Ukraine’s forces in the south, said that Ukraine had no choice but to withdraw.

“In a situation where the enemy is advancing on the corpses of their own soldiers with a 10-to-1 shell advantage, under constant bombardment, this is the only correct solution,” he said in a statement.