Newly mobilized Russian soldiers covering their forces’ retreat from western Kherson could face a rout at the hands of Ukrainian troops, according to the Institute for the Study of War (ISW).

The U.S. think tank said on Friday that Russia has started its withdrawal from the southern region and this was likely to continue over the next few weeks, but Vladimir Putin’s troops could face a struggle if Ukrainian forces choose to attack.

Ukraine’s Southern Operational Command has said Moscow is transferring ammunition, military equipment and units via ferry from the Dnipro River’s west bank to the east bank, while 2,000 Russian troops hold the frontline to cover their withdrawal by shelling Ukrainian positions.