UK says Russia is using separatist forces in eastern Ukraine; explosions reported in Kyiv

The city's mayor said there were explosions after missiles hit infrastructure. The city in the region reported enemy fire on Sunday.

CNBC couldn't confirm the reports because the situation on the ground is constantly changing.

The U.K. Ministry of Defence believes that Russia is trying to limit the number of casualties caused by its own troops.

Both sides claim to have gained territory in the eastern part of the country.

According to an NBC News translation, the head of Luhansk, Serhii Haidai, said that the city is now split between Russian and Ukrainian rule.

During the fighting between Ukrainian and Russian troops in the eastern Ukrainian region of Donbas, dirt and smoke rose in the city of Severodonetsk.

Aris Messiannis is pictured.

The official said that the city was 70% controlled by Russians two days ago. Eight Russians were taken prisoner and a lot of personnel were lost.

CNBC couldn't confirm the report at the moment. There is a rapid change in the situation on the ground in Ukranian.

In his nightly address, Ukrainian President Volodymyr Zelenskyy said that the situation in the city remained difficult.

The person is Christine Wang.

According to an NBC News translation, the city's mayor said several explosions were heard after missiles hit infrastructure.

One person was sent to the hospital and services were already working on the affected sites.

In the wake of reports of enemy fire in the area, the mayor of another city in the region urged residents to remain calm.

The report was not confirmed by CNBC. It is hard to confirm military developments on the ground.

The person is Christine Wang.

According to the U.K.'s Ministry of Defence, the Russian-led Separatist forces originate from Luhansk.

The forces lack heavy equipment and are poorly equipped, according to the ministry. The tactic of using proxy troops in Syria suggests a desire to limit casualties in Moscow's own forces.

The troop movements were not confirmed by CNBC. In the fluid situation on the ground, military developments can be hard to confirm.

The person is Christine Wang.