At least two buildings were damaged by a drone attack early on Monday in the Russian capital, Moscow, according to Russia, which has blamed Ukraine for the attack.
Two drones were "suppressed and crashed," the Russian defense ministry reported, adding that no one was hurt.
One drone reportedly crashed not far from the ministry of defense, according to the state-run Tass news agency in Russia.
Officials from Ukraine have not yet responded, but they infrequently take responsibility for attacks inside of Russia.
Separately, after a rumored overnight Ukrainian drone attack, Russian-installed officials in Crimea — the southern Ukrainian peninsula Moscow annexed in 2014 — ordered residents to leave one district.
According to Sergei Aksenov, the regional head appointed by the Kremlin, an ammunition depot was hit in the northern Dzhankoi area, and local villagers were ordered to evacuate. He said there had been none.
In the meantime, Ukraine reported that a Russian drone attack on two ports on the River Danube, a different export route to the Black Sea, in its southern Odesa region overnight injured four people and destroyed a grain hangar.
Since Russia withdrew from a historic grain deal last week, it has been attacking the Odesa region, which is home to Ukraine's major Black Sea ports, almost constantly.
Sergei Sobyanin, the mayor of Moscow, reported that "two non-residential" buildings were struck by drone attacks in the Russian capital at around 4:00 local time (01:00 GMT). He added that there had been no significant damage to the buildings in a social media post.
However, according to state news agencies, some drone fragments were discovered just 2km (1.22 miles) from the structures of the defense ministry.
The Russian defense ministry announced that an attempt by the Kyiv regime to commit a terrorist act by using two drones on targets on Moscow's territory had been thwarted.
Along the city's Komsomolsky Avenue, drone debris was also reportedly discovered, according to Russian news agencies. Traffic along the route was blocked, according to a Telegram post from Moscow's transport department, and images from the scene showed that emergency services were on the scene.
On Likhachev Avenue, where a tall office building was damaged, traffic was also stopped. The top of the building was seen to be missing windows in video that was broadcast on the military Zvezda TV channel.
In recent months, Russia has accused Ukraine of conducting a large number of drone attacks on its territory.
Russia claimed earlier this month that Ukraine had attacked Moscow with a drone, forcing flights out of Vnukovo International Airport. Ukraine made no apology for the incident.
A drone attack on the Kremlin that Russia claimed was an attempt on President Vladimir Putin's life was also denied by Kyiv in May.
The assault on Monday occurred the day after Russian missile strikes on Odesa destroyed the iconic Transfiguration Cathedral.
The attack on Odesa's historic center was "deeply dismayed" and "condemned in the strongest terms," according to Unesco, the UN's cultural agency.
Volodymyr Zelensky, the president of Ukraine, promised retaliation for the assault.
During his nightly address from Kyiv, he said, "They will definitely feel this.". "All of these missiles are not just aimed at cities, villages, or people. Humanity and the cornerstones of our entire European culture are their targets.