Russia-Ukraine updates: US sanctions Russian military shipbuilder, diamond miner

More evidence has emerged that some of the bodies seen lying in the streets of Bucha were there before Russian troops retreated from the Ukrainian town, northwest of Kyiv.

According to the U.K. Ministry of Defense, an analysis of satellite imagery dated March 21 identified at least eight bodies lying on a street in Bucha. The town was occupied by Russian forces until March 31, the ministry said in an intelligence update Tuesday night.

As Ukrainian troops regained control over Bucha, graphic images surfaced earlier this week showing numerous bodies of dead civilians -- some shot at close range and with their hands bound -- strewn across streets and in mass graves. Ukrainian authorities have accused Russia of committing war crimes. Russia has denied responsibility, calling the footage of Bucha "fake" and saying that all of its units withdrew completely from the town around March 30.

However, mounting evidence contradicts Russia's claims that the scene was "staged" after its troops left.

Russian missiles destroyed fuel storage facilities in five cities across Ukraine on Wednesday morning, Russia’s Ministry of Defense said.

"On the morning of April 6, high-precision air- and ground-based missiles destroyed 5 fuel storage bases near Radekhov, Kazatin, Prosyanaya, Nikolaev and Novomoskovsk,” the ministry claimed in its morning briefing. “These facilities have been used to supply fuel to Ukrainian military formations in Kharkov, Nikolaev and Donbass areas.”

European Union leaders said Wednesday they were preparing a new round of economic sanctions against Russia, as outrage grew over civilian deaths in the Ukrainian town of Bucha.

"We have all seen the haunting images of Bucha. This is what is happening when Putin's soldiers occupy Ukrainian territory," European Commission President Ursula von der Leyen said. "They call this liberation. I call this war crimes. The Russian authorities will have to answer for them."

The sanctions to be proposed may include a ban on importing Russian coal, bans on transactions with four Russian banks, and a ban on Russian ships at EU ports, among other measures.

The fifth round of sanctions "will not be our last," von der Leyen said. U.S. officials are also expected to announce new sanctions on Wednesday, sources told ABC News.

Russian forces are continuing their airstrikes in the besieged Ukrainian port city of Mariupol, according to the U.K. Ministry of Defense.

"The humanitarian situation in the city is worsening," the ministry said Wednesday in an intelligence update. "Most of the 160,000 remaining residents have no light, communication, medicine, heat or water."

Russian troops have prevented humanitarian access to the southern city, a move the ministry said was as part of a strategy to pressure Ukraine to surrender.