Ukraine war latest: Russian oil refinery on fire after drone attack - as Putin's forces trigger 'longest air raid alert' in major Ukrainian city since war began

We have reported this morning Russia claimed a Ukrainian drone attack caused a fire at an oil refinery in Krasnodar (see our 6.44am post).

Footage shared by The Wall Street Journal's chief foreign affairs correspondent, Yarsolav Trofimov, shows a fire at the Tuapse refinery.

The attacks may have been more successful than Russia lets on, with another video showing burning fuel depots at the Novorossiysk railway, also in Krasnodar.

Kim Yo Jong, the influential sister of North Korean leader Kim Jong Un, has again denied reports of arms exchanges with Russia - insisting the country's updated weapons systems are not for sale.

According to state-run KCNA, Kim Yo Jong said North Korea's recently-shown tactical weapons, such as rocket launchers and missiles, are for defence against South Korea, with the two countries technically still at war since their 1950-53 conflict ended in a truce, not a treaty.

The US and South Korea have accused North Korea of transferring weapons to Russia for its war in Ukraine.

Despite vowing to deepen military relations last year, both Moscow and Pyongyang have denied the accusations.

While ties between the two countries have strengthened dramatically in recent months, Kim Yo Jong said the North Korea-Russia arms deal "theory" made up of prejudice and fiction was the "most absurd theory", according to KCNA quoting her press statement.

She called it a false rumour spread by its hostile forces.

A Russian official claims a Ukrainian drone strike killed a mother and her four-year-old son in the southern region of Belgorod.

Vyacheslav Gladkov, the regional governor, says the pair were traveling in a car earlier today when one of several drones opened fire in the village of Oktyabrsky.

The woman died at the scene, while the boy died of his injuries at hospital.

The boy's father and a man driving the car were injured, but survived.

New satellite imagery appears to show damage at Belbek airbase in Russian-annexed Crimea.

Among the apparent targets were a fuel storage facility and several types of fighter jet.

Officials in Russia's Krasnodar region reported another Ukrainian drone attack on an oil refinery, this time causing a fire.

So far, no casualties have been reported at Tuapse oil refinery and authorities say they have contained the fire.

Meanwhile, Russia's defence ministry claims its air defence and the Black Sea fleet destroyed 102 Ukrainian drones and six unmanned boats overnight.

As a result of that attack, the governor of Sevastopol, in annexed Crimea, says an electrical substation was damaged.

"There will be isolated blackouts," he wrote on messaging app Telegram.

He says he has cancelled classes "in all schools, institutions of secondary vocational education and kindergartens".

As we reported last night, Ukrainian officials claimed Kharkiv region came under drone attack.

Some more information has now come to light.

Public broadcaster Suspilne reports the air raid alert lasted more than 16 hours - the longest recorded since Russia's invasion began.

Governor Oleh Syniehubov said at least five drones had struck Kharkiv, Ukraine's second largest city, while Mayor Ihor Terekhov said the city's Osnovyanskyi district had been hit, causing a fire.

There are no immediate reports of casualties or damage and the air raid alert was lifted early on Friday, after a missile warning was also in place.

Welcome back to our live coverage of the Ukraine war.

It's day two of Vladimir Putin's state visit to China after a summit with Xi Jinping yesterday, where the pair pledged a "new era" of partnership and signed a 7,000-word long joint statement reaffirming their deepening ties.

The Russian president is in the northeastern city of Harbin today, where he's expected to attend trade and cooperation forums and meet students at an engineering university.

The US brushed off the latest statement from the Chinese and Russian leaders - which included one-sentence warning on nuclear war - as "nothing new".

In other news from the past 24 hours:

• At least five Russian drones hit Kharkiv late last night, triggering a fire, before the city came "under missile attack", according to Ukrainian officials. There was no word on any victims;
• Moscow expelled a British defence attache in retaliation to the UK kicking out his Russian counterpart over spying allegations last week;
• Anti-Putin Russian paramilitary soldiers joined Ukrainian troops on the new frontier in northeastern Ukraine;
• Volodymyr Zelenskyy travelled to the city of Kharkiv following the fresh Russian incursion across Ukraine's northeastern border. He described the situation as extremely difficult though "controlled in general";
• Russian authorities claimed a Ukrainian attack in Russia-controlled Donetsk killed four people.

That's it for our live updates on the Ukraine war this evening.

Scroll through the blog below to catch up on what happened.

This map shows much of eastern Ukraine is under an air raid alert currently.

"Air defence is working, do not leave shelters and be careful," Kharkiv governor Oleh Synehubov said on Telegram.

Following on from our previous post, Kharkiv mayor Ihor Terekhov has now said that Kharkiv is "under missile attack".

This was also reported by regional governor Oleh Synehubov, who has urged citizens to move to air raid shelters.

Mr Synehubov said on Telegram that there is no information about victims currently.

A journalist in Kharkiv says he has "lost count of the number of explosions" shaking the city.