By Pavel Polityuk

KYIV Ukraine said Russia bombed a blood transfusion centre near the front line in a wave of air strikes overnight while Moscow reported that it had shot down a drone heading to the capital on Sunday in the third such attack in a week.

Both countries have stepped up attacks on each other's troops, weaponry and infrastructure supporting the war as Ukraine seeks to dislodge Russian forces who have dug in across southern and eastern Ukraine since their invasion last year.

The Moscow-appointed head of Crimea said the Chonhar bridge to the peninsula, which was annexed from Ukraine by Moscow in 2014, had been damaged by a missile strike. Another of the three road links between Crimea and Russian-occupied parts of mainland Ukraine, near the town of Henichesk, was shelled and a civilian driver wounded, a Moscow-appointed official said.

Traffic was halted on a third bridge, linking Russia to Crimea, after both sides said a Ukrainian naval drone full of explosives struck a Russian fuel tanker vessel overnight from Friday to Saturday, the second such attack in 24 hours.

The attacks are making it increasingly hard to get on and off the Black Sea peninsula, which is of military importance to Moscow as well as a popular tourist destination for Russians.

Inside Russia, Moscow's Vnukovo airport suspended flights on Sunday, citing unspecified reasons outside its control. Vnukovo imposed similar suspensions when Moscow was attacked by drones last week. Moscow mayor Sergei Sobyanin said a drone had been shot down on Sunday south of the capital.

At least 10 Russian missiles appear to have got through Ukraine's air defences in the overnight attack, which Ukraine's air force said involved 70 air assault weapons including cruise and hypersonic missiles as well as Iranian-made drones.

Local media said a worker at a grain silo had been wounded and a rescuer died during a rescue operation.

The attacks followed what President Volodymyr Zelenskiy said was a bomb attack on a blood transfusion centre in the town of Kupiansk, a railway hub around 16 km (10 miles) from the front in the eastern Kharkiv region.

"There are dead and wounded," he said on his Telegram channel, adding that rescue workers were extinguishing a fire at the scene and describing the strike as a "war crime".

He did not say how many casualties there were or whether they were military or civilian. Reuters could not immediately verify the report.

Russia denies deliberately targeting civilians or military hospitals in its full-scale invasion of Ukraine, which has killed thousands of people, uprooted millions and destroyed cities.

Russia's defence ministry said it had conducted successful strikes on Ukrainian air bases in the western Rivne and Khmelnytskyi regions and southern Zaporizhzhia region, without giving details.

Ukraine's air force said it destroyed 30 out of 40 cruise missiles and all 27 of the Shahed drones that Russia launched overnight. It also said Russia launched three Kinzhal hypersonic missiles, but did not disclose any further information on them.

It was not clear what happened to the 10 cruise missiles that were not shot down.

The deputy governor of the Khmelnytskyi region, Serhiy Tiurin, said a military airfield in Starokostiantyniv was among the targets. He said most of the missiles were shot down, but explosions had damaged several houses, a cultural institution and the bus station and a fire had broken out at a grain silo.

"Now, it is the Starokostiantyniv airfield that haunts the enemy," Ukrainian Air Force spokesman Yuriy Ihnat said.

Russia had targeted the airfield at the end of July.

PIPELINE LEAK

Poland halted oil flows through one part of the Druzhba pipeline carrying oil from Russia to Europe after detecting a leak, the latest hitch to energy flows since Russia invaded Ukraine. There was no indication of the cause and Germany said oil supplies were secure. Poland said it expected oil to flow again on Tuesday.

Ukraine is two months into a gruelling counteroffensive to try to push out Russian forces occupying almost a fifth of its territory in the south and east.

U.S. Secretary of State Antony Blinken said late last month that while Ukraine had recaptured half the territory that Russia had initially seized, the Ukrainian counteroffensive was in its early days and would take shape over "several months".

Another sea drone attack on Russia's navy base at Novorossiysk damaged a warship on Friday, the first time the Ukrainian navy had projected its power so far from its shores.

Former Russian President Dmitry Medvedev suggested Moscow would launch more strikes against Ukrainian ports in response to Kyiv's attacks on Russian ships in the Black Sea, and threatened to hand Ukraine "an ecological catastrophe".

Zelenskiy's aide Mykhailo Podoliak characterised the overnight Russian missile attacks as a response to Ukraine's overtures to Global South countries that have been reluctant to take sides in a conflict that has hurt the global economy.

Senior officials from some 40 countries including the U.S., China and India held talks in Saudi Arabia on Saturday and Sunday that Kyiv and its allies hope will lead to agreement on key principles for a peaceful end to Russia's war in Ukraine.

The two-day meeting is part of a diplomatic push by Ukraine to build support beyond its core Western backers. Zelenskiy's head of staff, Andriy Yermak, said they had been very productive discussions but did not give details.

Russia is not attending, though the Kremlin has said it will keep an eye on the talks. Ukrainian, Russian and international officials say there is no prospect of direct peace talks between Ukraine and Russia at present, with the war raging.

(Additional reporting by Lidia Kelly, Anna Wlodarczak-Semczuk and Vera Eckhert; writing by Philippa Fletcher; editing by Giles Elgood)