Early on Wednesday morning, the Ukrainian military states that Russian forces via air have entered the country's second largest city, Kharkiv, reports AFP.

"Airborne Russian forces have landed in Kharkiv ... and attacked a local hospital," the army wrote in a statement on Telegram.

"There are fighting going on between the aggressors and the Ukrainians," they added.

Civilians trapped

In recent days, Russian forces have stepped up their attacks on densely populated urban areas in Ukraine, and reports from several cities are coming of devastated residential areas following Russian attacks.

"Fierce fighting and shelling continue in several cities in Ukraine, with more and more victims and humanitarian consequences," the UN coordinator OCHA wrote in an update on the situation.

In several places, civilians are trapped and unable to escape the fighting.

Not only housing, but infrastructure such as water, sewage, electricity and roads have been destroyed, which affects hundreds of thousands of people, writes OCHA.

Apartment houses destroyed

In the city of Borodjanka, just over 50 km northwest of Kyiv, two large apartment buildings have been destroyed in what are said to be Russian airstrikes.

Videos whose authenticity The New York Times has verified show how a structure is burning and how parts of the houses have been demolished.

There is no confirmed information yet about those killed or injured, but witnesses tell in the films how they have heard people shouting during the landslides and how they are looking for survivors.

On Tuesday, an apartment complex next to a hospital in the country's second largest city, Kharkiv, was also met, reports CNN, which has verified the authenticity of film material showing the devastation in the area.

A video shows a fire raging at a damaged apartment building, across the street from the hospital.

The examined video material also shows a couple of dead bodies.

The attack is said to have taken place a few hours after Kharkiv's central square was shelled with what is believed to have been a robot.

Cities surrounded

There are also reports that a maternity clinic has been set up near Kyiv.

“A robot hit the maternity clinic.

The damage is great, but the building stands.

Everyone has been evacuated, "writes the clinic's head Vitaly Gyrin on Facebook.

The British Ministry of Defense says in an update that the number of Russian air and artillery attacks has intensified in the last two days.

"Ukrainian forces still control Kharkiv, Kherson and Mariupol, but all three cities are likely to be surrounded by Russian forces," the ministry said.

On Wednesday morning, however, it seems that Russian forces have taken over the city, based on photos and films that CNN has taken part in.

Logistics problems

According to Ukraine, more than 350 civilians, including 16 children, have been killed in the war so far, but the numbers of deaths are difficult to verify and very uncertain.

Early next week, the ICC war crimes tribunal in The Hague will open public hearings on Russia's allegations of genocide in the Donetsk and Luhansk regions.

In its application to the court, Ukraine has denied these allegations and instead accuses Russia of planning a genocide in Ukraine, reports CNN.

At the same time, a US defense source states that Russia's military advancement has slowed down, reports AP.

It includes the over 60 km long column located just north of Kyiv.

The column has not been able to move forward due to logistical problems, according to the defense source.

It is about lack of fuel and food and as a result, the fighting morale of the Russian soldiers has dropped, according to the source.