A munitions depot near the Ukrainian city of Kharkiv caught fire and was rocked by a series of explosions in a huge conflagration that authorities blamed on "sabotage," prompting the evacuation of thousands of people living nearby.
President Petro Poroshenko on March 23 pointed the finger at Russia, saying it was "no accident" that they occurred on the day that a former Russian lawmaker who has criticized Russia's government was shot dead in Kyiv.
The fires broke out overnight at the depot on an army base in Balaklia, near Kharkiv and around 100 kilometers from the front line in the conflict between government forces and Russia-backed separatists further southeast.
As of the evening of March 23, about 20,000 residents living within a 20-kilometer radius of the depot had been evacuated, officials said.
Prime Minister Volodymyr Hroysman told reporters in the Kharkiv region that one woman was seriously injured in the explosions and that "the territory is still very dangerous."
"We can evaluate everything as the intensity of the fire decreases," he said in televised comments. "This can take up to one week."
He said 550 emergency workers, medical officers, and police had been sent to the site to aid recovery efforts.
The depot, which stores 138,000 tons of ammunition including artillery shells and missiles, is used to supply Ukrainian forces fighting against the separatists.
Chief military prosecutor Anatoliy Matios wrote on Facebook that investigators on the scene believed the fire and subsequent explosions were the "result of sabotage."
Officials said some 20,000 residents in the area were being evacuated.
Defense Minister Stepan Poltorak said that one-third of the 368-hectare depot was on fire, adding that the situation might get worse if the fire reaches underground storage areas, where long-range cannon shells are being kept.
Poltorak also said that aircraft were barred from a 50-kilometer zone around Balaklia as the blasts were scattering shells as far as 2 kilometers from the site.
Ukraine's Security Service (SBU) said that it had launched an investigation on suspicion of "sabotage."
Poroshenko also called it sabotage and said it was "no accident" that the munitions depot fire and the killing of former Russian lawmaker Denis Voronenkov, who moved to Ukraine last year, occurred on the same day.
In a statement posted on Twitter and Facebook, Poroshenko said that Voronenkov's killing was a "act of state terrorism" by Russia.
He issued the statement after meeting with senior security officials to discuss the situation in Balaklia and the Voronenkov killing.
Ammunition depot fires occur frequently in the former Soviet Union.
Poltorak also said the blasts could have been set off deliberately, and that the same depot had been set on fire by saboteurs using drones in 2015.
The war between government forces and Russia-backed separatists who control parts of the Donetsk and Luhansk regions, both of which border the Kharkiv region, has killed more than 9,900 people since April 2014.
It continues despite a February 2015 agreement on a cease-fire and steps to end the conflict.
Poltorak said that security had been tightened around all military depots across the country.
Regional natural-gas supplier Kharkivgaz suspended gas delivery to Balaklia to avoid further explosions, and all rail service near the area was suspended.
With reporting by RFE/RL's Ukrainian Service, UNIAN, and Begemot.media