Experts say a string of Russian attacks against rail and fuel installations far from the front lines of Moscow's new eastern offensive were aimed at demonstrating Russian capabilities as much as disrupting Ukraine's ability to fight.
On Monday local time, Russian missiles and warplanes hit five railway stations in central and western Ukraine, killing one worker, said Oleksandr Kamyshin, head of Ukraine's state railway Ukrzaliznytsia.
"Russian troops continue to systematically destroy railway infrastructure," he said in a statement.
In a separate statement, Ukrzaliznytsia said there was no power on the Shepetivka–Koziatyn, Zhmerynka–Koziatyn, and Koziatyn–Fastiv lines, forcing delays.
Mr Kamyshin said the attacks had delayed at least 16 passenger trains.
The Institute for the Study of War (ISW), in a daily update, said "a series of likely coordinated Russian missile strikes conducted within an hour of one another" hit in the Vinnytsia, Poltava, Khmelyntskyi, Rivne and Zhytomyr regions.
The bombardment included a missile attack near Lviv, the western city close to the Polish border that has been swelled by Ukrainians fleeing the fighting elsewhere around the country.
Regional governor Maksym Kozytskyy said a Russian missile hit a railway facility in Krasne, about 40 kilometres east of Lviv, sparking a fire.
In the central Vynnytsia region, regional prosecutors said at least five people were killed and another 18 wounded in missile strikes on the towns of Zhmerynka and Koziatyn.
Vynnytsia regional governor Serhiy Borzov said earlier that the Russian missiles targeted "critical infrastructure," but did not say if that included railway facilities.
The Vynnytsia region is fully controlled by Ukraine and is far behind the front lines.
Russia has consistently denied targeting civilians or intending to overthrow Ukraine's government.
Strikes a new tactic against key resources
In a Facebook post, Ukraine's military command said Russia was trying to disrupt arms supplies to Ukraine from its allies.
"They are trying to destroy the supply routes of military-technical assistance from partner states. To do this, they focus strikes on railway junctions," the armed forces command wrote.
Russia's defence ministry said later its missiles destroyed six facilities powering railways it said were used to deliver foreign weapons to Ukrainian forces in the eastern Donbas region.
The ISW said the strikes were strategic but may also have been a deliberate demonstration of Russian abilities.
"The Kremlin may have additionally conducted this series of strikes — an abnormal number of precision missile strikes for one day — to demonstrate Russia's ability to hit targets in western Ukraine and to disrupt western aid shipments," the institute said.
However, the institute said Russia's precision strike capabilities would remain too limited to decisively affect the course of the war.
It pointed to an April 24 report from open-source research organisation Bellingcat that Russia had likely already used 70 per cent of its total stockpile of precision missiles.
Philip Breedlove, a retired US general who was NATO's top commander from 2013 to 2016, said there was a darker motivation behind the strikes.
He said although strikes against fuel depots were part of a strategy to deplete key Ukrainian war resources, the attacks on rail targets were a newer tactic.
"I think they're doing it for the legitimate reason of trying to interdict the flow of supplies to the front," he said.
The United Nations High Commission for Refugees (UNHCR) says more than 5.2 million Ukrainians have fled the country since Russia invaded, more than half of them children.
The number exceeds the UNHCR's worst predictions.
Attacks followed train journey by top American envoys to Kyiv
The attacks came shortly after America's Secretary of State Antony Blinken and Defense Secretary Lloyd Austin returned to Poland after travelling overland to Kyiv for a meeting with President Volodymyr Zelenskyy.
The White House, citing security concerns, had not released details of the trip before the meeting, which was announced ahead of time by Mr Zelenskyy.
Journalists who travelled with Mr Austin and Mr Blinken to Poland were barred from reporting on the trip until it was over, were not allowed to accompany them on their overland journey into Ukraine and were prohibited from specifying where in south-east Poland they waited for the cabinet members to return.
"We certainly saw people on the streets of Kyiv, evidence of the fact that the battle for Kyiv was won," Mr Blinken said after the meeting, providing glimpses of the train journey from Poland.
The envoys said the US would provide new military assistance of more than $US300 million ($417 million) in military financing and had approved a $US165 million sale of ammunition.
Train stations have been attacked before
On April 8 in Kramatorsk, in eastern Ukraine, two ballistic missiles exploded over the railway station building, killing 59 and injuring hundreds more.
About 4,000 people, most of them elderly, women and children, were at the station when it was struck, Kramatorsk Mayor Oleksander Honcharenko said.
Russia's Defence Ministry denied launching a missile strike on the station, saying its army had no targets assigned in Kramatorsk.
Ukrainian President Volodymyr Zelenskyy said there were no Ukrainian troops at the station when the attack occurred.
Ukraine's Prosecutor General Iryna Venediktova described the deadly missile strike on a rail station as a "crime against humanity."
Pavlo Kyrylenko, governor of the Donetsk region, said the Russians "knew very well where they were aiming and what they wanted".
ABC/wires
