A Russian officer surrendered and sold out his comrades, helping Ukraine's special forces cross a key river

• A Russian officer helped Ukrainian special forces secure a key river this fall, the AP reported.
• The report said the officer and 11 other troops surrendered along the Dnipro River.

A Russian officer who said he opposed the invasion of Ukraine surrendered and provided intel that helped Ukrainian special forces secure part of a key river this fall, the Associated Press reported.

Amphibious troops with Ukraine's elite Center 73 special-forces unit had been trying for months to take Russian positions along the Dnipro River, the AP reported.

But after Russian forces blew up a dam upstream and flooded villages and towns in June, Ukrainian forces were forced to pull back. By the time the waters receded in July, Russian troops were able to retake their side of the river, according to the AP.

The AP report said that one unit of Center 73 was tasked with retaking an island near the village of Krynky but that the Kremlin's forces drove them off under a hail of gunfire and Iskander missiles.

Not long after that, a Russian officer who said he opposed the war was transferred to the front lines, the report said. The officer approached Ukrainian intelligence and offered to surrender along with 11 other troops he said were also disillusioned with Russian President Vladimir Putin's invasion, the outlet reported.

The Russian troops surrendered to Ukrainian special forces and fed them information about the remaining Russian forces, the AP reported.

That helped the special forces stage a breach in the Russian position and establish control of an occupied village across the river, the report said. Ukraine still holds the area.

The foothold is a small breakthrough in a war that has become a grinding, bloody stalemate between Ukrainian defenders and Russia's invasion forces. Beyond the bridgeheads, the Dnipro remains a formidable natural barrier between Ukraine and Russian-occupied territory.