Massive explosions and fires hit a military depot in Russia-annexed Crimea on Tuesday, forcing the evacuation of more than 3,000 people, the second time in recent days that the Ukraine war's focus has turned to the contested peninsula.

Russia blamed the blasts at an ammunition storage facility in Mayskoye on an "act of sabotage" without naming the perpetrators. As with last week's explosions, they led to speculation that Ukrainian forces may have staged an attack on the peninsula, which Russia has controlled since 2014.

Separately, the Russian business newspaper Kommersant quoted local residents as saying that plumes of black smoke also rose over an air base in Crimea's Gvardeyskoye.

Ukraine has stopped short of publicly claiming responsibility for any of the fires or explosions, including last week's at another air base that destroyed nine Russian planes. If Ukrainian forces were, in fact, responsible for any of the explosions, they would represent a significant escalation in the war.

Videos posted on social media showed thick plumes of smoke rising over raging flames in Mayskoye, and a series of explosions could be heard in the background. The Russian Defense Ministry said the fires at the depot caused damage to a power plant, power lines, rail tracks and some apartment buildings. It said in a statement that "there were no serious injuries."

Earlier, Russia's state news agency RIA Novosti reported a fire a transformer substation after "a loud thump sound" in what appeared to be a result of the blasts at the depot.

Crimea holds huge strategic and symbolic significance for Russia and Ukraine. The Kremlin's demand that Kyiv recognize the peninsula as part of Russia has been one of its key conditions for ending the fighting, while Ukraine has vowed to drive the Russians from the peninsula and all other occupied territories.

The district where the blasts happened, Dzhankoi, is in the north of the peninsula, about 50 kilometers (30 miles) from the Russian-controlled region of Kherson in southern Ukraine. Kyiv has recently mounted a series of attacks on various sites in the region, targeting supply routes for the Russian military there and ammunition depots.

Last week's explosions at Saki air base sent sunbathers on nearby beaches fleeing as huge flames and pillars of smoke rose over the horizon. Ukrainian officials emphasized Tuesday that Crimea — which is a popular destination for Russian tourists — would not be spared the ravages of war experienced throughout Ukraine.

Rather than a travel destination, "Crimea occupied by Russians is about warehouses explosions and high risk of death for invaders and thieves," Ukraine presidential adviser Mykhailo Podolyak said on Twitter, though he did not claim any Ukraine responsibility for the blasts.

Crimea's regional leader, Sergei Aksyonov, said that two people were injured and more than 3,000 evacuated from the villages of Mayskoye and Azovskoye near Dzhankoi following the munitions depot explosions. who can we attribute the injured to?

Because the explosions damaged rail tracks, some trains in northern Crimea were diverted to other lines.

The Russian military blamed last week's blasts at the Saki air base on an accidental detonation of munitions there, but it appeared to be the result of a Ukrainian attack.

Ukrainian officials at the time stopped short of publicly claiming responsibility for the explosions, while mocking Russia's explanation that a careless smoker might have caused the ammunition to catch fire. Analysts also said that explanation doesn't make sense and that the Ukrainians could have used anti-ship missiles to strike the base.

A British Defense Ministry intelligence update said vessels in Russia's Black Sea Fleet "continue to pursue an extremely defensive posture" in the waters off Crimea, with the ships barely venturing out of sight of the coastline.

Russia already lost its flagship Moskva in the Black Sea and last month the Ukrainian military retook the strategic Snake Island outpost off Ukraine's southwestern coast. It is vital for guaranteeing sea lanes out of Odesa, Ukraine's biggest port.

The Russian fleet's "limited effectiveness undermines Russia's overall invasion strategy," the British statement said. "This means Ukraine can divert resources to press Russian ground forces elsewhere."

Meanwhile, in the Donbas, which has been the focus of the fighting in recent months, one civilian was killed in Russian shelling, and two others wounded, according to the Ukrainian governor of the Donetsk region, Pavlo Kyrylenko.

In Kharkiv, Ukraine's second-largest city, one civilian was killed and nine others were wounded by Russian shelling, regional governor Oleh Syniehubov said. He added that the overnight attack on the city was "one of the most massive shelling of Kharkiv in recent days."

Officials in the central region of Dniprotpetrovsk also reported shelling of the Nikopol and the Kryvyi Rih districts.