Russia denied involvement in a rocket attack that killed dozens of people at a train station in eastern Ukraine on Friday.

Kremlin spokesman Dmitry Peskov alleged that the involvement of Russian forces in the attack on the railway station in the Ukrainian city of Kramatorsk was already ruled out by the Russian Ministry of Defense, based on the type of missile that was used -- a Tochka-U short-range ballistic missile.

"Our Armed Forces do not use missiles of this type," Peskov told reporters during a press briefing Friday. "No combat tasks were set or planned for today in Kramatorsk."

The head of the European Commission, Ursula von der Leyen, and the bloc's top diplomat, Joseph Borrell, were due to arrive in Ukraine's capital on Friday.

While in Kyiv, the pair will meet with Ukrainian President Volodymyr Zelenskyy. It will be their first visit to the Ukrainian capital since Russia launched its invasion on Feb. 24.

At least 30 people were killed and more than 100 others injured in a rocket attack on a railway station in eastern Ukraine on Friday morning, authorities said.

According to Ukraine's state-owned railway company, two Russian rockets struck the train station in the city of Kramatorsk in Donetsk Oblast.

"This is a purposeful strike on the passenger infrastructure of the railway and the residents of the city of Kramatorsk," Ukrainian Railways said in a post on Facebook.

Donetsk Oblast Gov. Pavlo Kyrylenko said the station was teeming with civilians fleeing the Russian invasion. Kyrylenko accused Russian forces of wanting "to take as many peaceful people as possible."

"Thousands of people were at the station during the missile strike, as residents of Donetsk Oblast are being evacuated to safer regions of Ukraine," Kyrylenko said in a post on Telegram.

Ukrainian President Volodymyr Zelenskyy confirmed that "thousands of peaceful Ukrainians were waiting for evacuation" when the rockets hit the station.

"Not having the strength and courage to confront us on the battlefield, they are cynically destroying the civilian population," Zelenskyy said in a post on Facebook. "This is an evil that has no limits. And if it is not punished, it will never stop."

Graphic images provided by Ukrainian officials showed the aftermath of the attack -- bodies lying on the ground next to scattered luggage and debris, with charred vehicles parked nearby.

Russian forces in northern Ukraine have now fully withdrawn to neighboring Belarus and Russia, the U.K. Ministry of Defense said Friday in an intelligence update.

"At least some of these forces will be transferred to East Ukraine to fight in the Donbas," the ministry added. "Many of these forces will require significant replenishment before being ready to deploy further east with any mass redeployment from the north likely to take at least a week minimum."

Meanwhile, cities in eastern and southern Ukraine continue to be shelled by Russian forces as the troops advance "further south from the strategically important city of Izium which remains under their control," according to the ministry.

Russia's invasion of Ukraine has already engaged around 330,000 Russian personnel, Brigadier General Oleksiy Hromo of the General Staff of the Ukrainian Armed Forces told local media on Thursday.

“[Russian] groups at various axes are close to 150,000 strong. If we add their air and sea components, there are about 220,000 military personnel,” Hromo said. Russia also deployed “units of the national army combat reserve, the federal service of guard forces, and mobilization units,” the Brigadier General added.

Hromo's sobering account came on the back of claims made by a top Ukrainian official earlier on Wednesday that revealed mounting Ukrainian casualties. Up to 1,000 Ukrainian soldiers are being killed or wounded each day in the Donbas region of eastern Ukraine, with 200 to 500 killed on average and many more wounded, said David Arakhamia, who heads the presidential faction in the Ukrainian parliament.

In early June, Ukrainian President Volodymyr Zelenskyy said daily fatalities among Ukrainian ranks at the Donbas front were between 60 to 100 troops.

Arakhamia, one of Zelenskyy's closest advisers who oversees Ukraine's stalled negotiations with Russia, has been leading a Ukrainian delegation in Washington this week in a bid to lobby the Biden administration and Congress.

Arakhamia's team want to see the pace of weapons shipments increased and is pushing for a designation of Russia as a state sponsor of terrorism.

-ABC News' Edward Szekeres, Yuriy Zaliznyak, Yulia Drozd and Max Uzol