At least two people were killed Wednesday as Ukraine was hit by reportedly the largest Russian aerial attack in weeks.

Ukraine said it had downed more than two dozen cruise missiles and a swarm of attack drones across the country in the "most powerful" aerial attack on Kyiv since the spring.

The assault came as Russia said an airport near the border with NATO member Estonia had been targeted by drones, and state news agencies reported several transport planes were damaged.

An AFP reporter in Kyiv heard at least three loud explosions over the capital at around 5 a.m. (2 a.m. GMT) as part of the nationwide barrage of 28 cruise missiles and 16 attack drones.

The Kyiv City Military Administration described the barrage as the largest to hit the city since the spring, and two people were killed by falling debris, Sergiy Popko, a military official in Kyiv announced.

Emergency services said the victims were employees of an infrastructure facility in the Shevchenkivsky district, without elaborating.

Russian forces launched groups of Iranian-made Shahed attack drones at the capital from different directions, and launched missiles from aircraft, the Kyiv city military administration said.

AFP reporters saw municipal workers assessing damage to the roof of a housing block where residents were clearing debris from flats with blown-out windows.

Drone wave

And law enforcement cordoned off forested territory where tangled pieces of metal had landed following the overnight attack.

Russia systematically targeted Ukrainian cities early in the invasion launched last year but massive strikes have lessened as Moscow's stockpiles depleted and Ukraine bolstered its air defenses.

Ukraine has meanwhile stepped up drone attacks inside Russia.

It launched a wave of strikes overnight, targeting an airport near the Estonian border and the Crimean peninsula on the Black Sea, Russian authorities said.

The governor of the Pskov region bordering Estonia said air defense systems had repelled drones targeting the airfield roughly 800 kilometers (nearly 500 miles) from Ukraine's border.

Gov. Mikhail Vedernikov, who said he was at the scene of the attack, posted a video online of a massive fire, with the sounds of explosions and sirens in the background.

Authorities were assessing the damage but there were no casualties, he said.

The RIA Novosti agency cited the emergency situations ministry as saying two Ilyushin Il-76 heavy transport planes had caught fire. TASS reported four were implicated in the attack.

There was no immediate comment from the defense ministry.

All flights scheduled Wednesday at the airport were cancelled, Vedernikov announced, "until the nature of the possible damage to the runway is clarified."

Black Sea tensions

The Pskov region was previously targeted by drones in May.

Authorities in Bryansk region near the Ukraine border, southern Oryol region and Kaluga and Ryazan regions, southwest and southeast of Moscow, all reported drones had been destroyed or downed.

Air defenses also destroyed a drone "heading for Moscow," the city's mayor wrote on social media, adding there were no casualties or damage caused.

The state-run TASS news agency reported that Moscow's Domodedovo and Vnukovo airports had been "temporarily closed to traffic.

Moscow and other Russian regions have been targeted by almost daily drone strikes since Kyiv vowed this summer to "return" the conflict to Russia.

Tensions have also been building on the Black Sea since Moscow exited a deal allowing maritime exports from Ukraine, and threatened to attack cargo ships using Ukrainian ports.

Russia's Defense Ministry said early Wednesday one of its aircraft "destroyed four high-speed military boats" in the Black Sea around midnight Moscow time.

It said the vessels were carrying Ukrainian special forces and claimed several dozen personnel had been killed, without giving details on exactly where in the Black Sea the incident took place.

Early Wednesday, Russian defenses also repelled a "seaborne drone attack" near Sevastopol in Crimea, the Moscow-installed Gov. Mikhail Razvozhayev was cited as saying by the state-run TASS news agency.

Sevastopol is the base of Russia's Black Sea fleet.

Both Ukraine and Russia have ramped up activity around the strategic waterway after the United Nations-brokered deal to ensure safe navigation for grain ships collapsed last month.

In recent weeks, Kyiv has attacked Russian ships in its waters and the Crimean Peninsula, which was annexed by Moscow in 2014.

Last week, Ukraine said its forces had flown the country's flag in Crimea during a "special operation" to mark its second wartime Independence Day.