The Russian Defense Ministry claimed that the military hit two S-300 defense systems belonging to Ukraine on Sunday

"Two S-300 air defense missile launch systems and radars were destroyed near Shpilevka in the Sumi region," said ministry spokesperson Igor Konashenkov.

Russian air combat tactical units targeted 32 more areas where Ukrainian soldiers and technical vehicles were located, he added.

"To date, 165 aircraft, 125 helicopters, 879 unmanned aerial vehicles, 306 air defense missile systems, 3,098 tanks and armored vehicles, 381 multi-barrel rocket launchers, 1,525 howitzers and mortars, and 2,934 special military vehicles belonging to the Ukrainian army have been destroyed," said Konashenkov.

At least 3,573 people have been killed and 3,816 injured since Russia launched the war on Ukraine on Feb. 24, according to U.N. estimates. The true toll is feared to be much higher.

Over 6.1 million people have fled to other countries, with some 7.7 million people internally displaced, according to the United Nations High Commissioner for Refugees (UNHCR).