A roaring, smoky fire at what Russian authorities initially said was a military training ground on Crimea but then later called a landfill forced the evacuation of thousands of villagers in the early hours of Wednesday.
Several Russian military bloggers and some news reports in Ukraine said that Ukrainian projectiles had struck an ammunition dump on a military base used for training, and that it continued to burn for hours after it first erupted. The Kremlin-appointed head of Crimea, Sergei Aksyonov, also said the fire was raging at a military camp.
President Vladimir V. Putin of Russia, however, said in brief remarks at the Kremlin that the conflagration was at a landfill. “Everything will burn out and end, but you have to be very careful,” Mr. Putin said, according to a report on the Telegram channel of Zvezda News, the news agency run by Russia’s Ministry of Defense.
Although Russian officials said that the cause of the blaze was still under investigation, they also reported heavy Ukrainian drone activity in the same part of eastern Crimea just before reports of explosions and fire. A few other reports said that long-range Ukrainian missiles had struck the target.
Ukraine made no outright claims of responsibility.
Mr. Aksyonov, the Russian-appointed head of the peninsula, wrote on his Telegram channel that some 2,000 people were evacuated from four villages near what he called a training ground in the Kirovsky district.
The fire also forced the closure of the Tavrida highway, the main, four-lane highway that runs from Simferopol to the Kerch Strait Bridge, which was hit and badly damaged in what appeared to be a Ukrainian marine drone strike early Monday.
The shift in the description of the site of the blast made it appear as if the Kremlin were trying to play down the likelihood that two Ukrainian attacks in three days had interrupted transportation links on the Crimean Peninsula.
Ukraine has made no secret that among the goals of its counteroffensive, begun over a month ago, is the disruption of transport and other military activity on Crimea, which is a major transit point for military supplies headed into the occupied areas of southern Ukraine. Russia seized the peninsula from Ukraine in 2014 and has made it the home base of Russia’s Black Sea fleet.