Russia’s invasion of Ukraine has resulted in the death of at least  352 civilians since Thursday, Kyiv said earlier on Tuesday. The death toll includes 14 children.

In a separate incident, more than 70 Ukrainian soldiers were killed at a military base in Okhtyrka, a city between Kharkiv and Kyiv. The head of the region said in social media post that the deaths were reported after Russian artillery hit the military base.

Dmytro Zhyvytskyy also posted pictures of the charred shell of a four-story building and rescuers searching rubble. He later said in a Facebook post that the Russian forces also suffered casualties in the fight.

The news comes after the first round of negotiations between Ukraine and Russia were unfruitful, further escalating tensions between the two countries.

Russia’s entry into Ukraine has also sent nearly 500,000 people have fled Ukraine since Russia invaded the country last week.

Russian forces were also seen traveling in a 40-mile long convoy towards Ukraine’s capital city, Kyiv. The satellite images shared by US-based company Maxar Technologies showed armored vehicles, tanks, artillery and support vehicles was 17 miles (25 kilometers) from the center of Kyiv, according to reports from Associated Press.  

With Russia’s march towards Kyiv moving forward, lawmakers in the United States have also expressed concern. Chris Murphy, a Senator from Connecticut and a member of the Democratic Party, predicted that Kyiv may be cut off by Russian forces in coming weeks. 

While citing intelligence reports, Murphy said, “The fight for Kyiv will be long and bloody and Ukrainians are rapidly preparing for street to street combat”, according to reports from Guardian.

Russia has also been accused of using ‘vacuum bombs’ in Ukraine by Oksana Markarova, Kyiv’s ambassador to the United States. Human rights groups like Amnesty International and Human Rights Watch have released separate reports making similar claims.