Russia fights back despite troop shortage, Ukraine's recent gains

It is battling Kyiv's forces in the south, may redeploy troops to protect Crimea

The Kremlin is on the back foot after suffering a military reversal in Ukraine, but its forces are still holding key positions in the Donbas region and putting up a fierce fight against Kyiv's troops near Kherson in the south.

There are signs the Kremlin may also be redeploying forces to protect Crimea, which Russia annexed as the main prize of its 2014 campaign, in the event Ukraine is able to break through its lines.

In the Kremlin, the shock at the sudden and striking battlefield reversals is increasingly giving way to a grim resignation and a determination to continue escalating the fight, stepping up strikes on Ukraine's infrastructure deep behind the lines, according to people familiar with the situation who spoke on condition of anonymity.

Publicly, Russia denies aiming at civilian targets, which would be a violation of international law.

But after strikes on power plants plunged large areas of Ukraine into darkness on Sunday, Russia late on Wednesday fired missiles at elements of the water system in Kryvyi Rih, causing severe damage and flooding in a city behind the front lines, Ukraine said.