KYIV, Sep 23 (AFP) - Ukraine claimed responsibility for a missile attack that struck the headquarters of Moscow's Black Sea fleet in annexed Crimea Friday, leaving one missing and sparking a fire.

Ukraine has targeted Crimea throughout Russia's offensive but attacks on military installations there have recently intensified.

"Around 12:00 (0900 GMT), Ukraine's Defence Forces launched a successful attack on the headquarters of the command of the Black Sea Fleet of Russia in the temporarily occupied Sevastopol," the Ukrainian army's communication department said on Telegram.

Sevastopol, home to Russia's Black Sea Fleet, has been increasingly targeted as Kyiv has vowed to take back the peninsula, which Russia annexed in 2014.

"I would like to thank the air force pilots once again," Ukrainian air force commander Mykola Oleshchuk said after the strike.

The Russian defence ministry said one serviceman was missing, after initially reporting one dead in the attack.

"The historic headquarters building of the Black Sea Fleet was damaged," it said, adding air defence had shot down five missiles.

"The headquarters of the fleet have been hit in an enemy missile attack," Mikhail Razvozhayev, the governor of Crimea's largest city Sevastopol, had said on social media.

Razvozhayev said that missile fragments had fallen near a theatre and urged residents to stay clear of the site.

Ten residential buildings were lightly damaged, he said, but "no one was wounded."

* Cyberattack

He had warned that another aerial attack could be imminent, urging residents of the city, which is home to more than 500,000 people, to remain indoors.

"Attention everyone! Another attack is possible. Please do not go to the city centre. Do not leave buildings," he said.

"Everyone who is near the headquarters of the fleet -- at the sound of the siren proceed to shelters," Razvozhayev added.

He said rescue workers were at the scene, adding: "Firefighters are taking all measures to eliminate the fire as soon as possible."

The peninsula was also hit by an "unprecedented cyberattack" on its internet providers, said Oleg Kryuchkov, an adviser to the Moscow-installed Crimea governor.

Ukrainian and Russian attacks in and around the Black Sea have increased since Moscow withdrew from an accord that allowed safe passage to civilian cargo ships from three Ukrainian ports.

Ukraine has urged its allies to provide its armed forces with long-range missiles so it can target positions deeper inside Russia-controlled territory.

Western leaders had hesitated over concerns Ukraine could target Russian territory and thereby escalate the conflict.

Both France and the United Kingdom had, however, supplied Kyiv's forces with the weapons.

* Airfield struck

As part of the increasingly frequent strikes targeting Crimea, Ukraine said earlier this week it had struck a military airfield near the town of Saky.

A source in Ukraine's SBU security service said there were at least a dozen warplanes and Pantsir missile defence systems at the airfield when the attack took place.

The airfield also housed a training centre for operators of drones that Russia uses to target Ukraine.

The SBU source said that Ukraine had deployed a swarm of unmanned aerial vehicles which "overwhelmed Russian air defenses" and then launched Neptune cruise missiles.

Kyiv has also repeatedly targeted -- and hit -- the only bridge that connects the peninsula to the Russian mainland, on several occasions leaving damage that took weeks to repair.

The last major attack in July impacted the road section of the bridge, which can accommodate rail traffic and is also used to transport military equipment.

Russian officials said on Friday that traffic across the bridge had been temporarily paused.

Civilian maritime traffic was stopped earlier on Friday in Sevastopol, Russian-installed authorities said, without providing details.