Russia has warned of further gas suspensions if “unfriendly countries” continue to take action against Moscow and do not pay for supplies under the new requirement to use roubles.

President Vladimir Putin also warned “if someone from the outside tries to intervene in Ukraine” the “response will be lightning fast”.

“We have all the tools [to respond] that no one can boast of. And we will not be bragging about them, we will use them if necessary,” Mr Putin said.

Russia’s state-run energy company Gazprom has already halted gas supplies to Bulgaria and Poland – in a move the European Union Commission president Ursula von der Leyen said was an act of aggression and form of blackmail.

“We will ensure that Gazprom’s decision has the least possible impact on European consumers,” Ms von der Leyen said.

She also warned European energy providers against complying with Russian demands to pay for energy in roubles.

“To pay in roubles, if that is not foreseen in the contract, is a breach of our sanctions,” Ms von der Leyen said.

President Vladimir Putin has demanded “unfriendly” countries to pay for gas imports in roubles. Photo: Getty

Bulgarian and Polish leaders have reassured their citizens there will be enough gas because they have shored up alternatives from other countries.

Prime Minister Kiril Petkov said he had spoken to the Greek government.

Poland said Germany and Czech Republic was providing its residents with gas.

Russia stopped the two countries from receiving gas as punishment for rejecting the Moscow’s demand for payment in roubles, taking direct aim at European economies in its toughest retaliation so far against international sanctions over the war in Ukraine.

The step was denounced by European leaders as “blackmail”, and comes as European countries have joined the United States in ramping up arms shipments to help Ukraine fend off a new Russian assault in the east.

Meanwhile, Ukraine reported on Wednesday that Russian troops had made gains in several villages there.

Russia reported a number of blasts on its side of the border, and a blaze at an arms depot. Kyiv called the explosions “karma”.

Read on for more of the latest news on Ukraine.

Blasts in Russia called ‘karma’

Russia has reported a series of blasts in the south of the country and a fire at an ammunition depot, the latest in a spate incidents that a top Ukrainian official described as payback and “karma” for Moscow’s invasion.

Without directly admitting that Ukraine was responsible, presidential adviser Mykhailo Podolyak said it was natural that Russian regions where fuel and weapons are stored were learning about “demilitarisation”.

The use of that word was a pointed reference to Moscow’s stated objective for the nine-week-old war in Ukraine, which it calls a special military operation to disarm and “denazify” its neighbour.

“If you (Russians) decide to massively attack another country, massively kill everyone there, massively crush peaceful people with tanks, and use warehouses in your regions to enable the killings, then sooner or later the debts will have to be repaid,” Mr Podolyak said.

The blasts on Wednesday followed a major fire this week at a Russian oil storage facility in the Bryansk region near the border.

Earlier this month, Russia accused Ukraine of attacking a fuel depot in Belgorod with helicopters, which a top Kyiv security official denied, and opening fire on several villages in the province.

The incidents have exposed Russian vulnerabilities in areas close to Ukraine that are vital to its military logistics chains.

In the latest incidents, Belgorod regional governor Vyacheslav Gladkov said a fire at an ammunition depot had been extinguished and no civilians have been injured.

Roman Starovoyt, the governor of Kursk, another province that borders Ukraine, said explosions had also been heard in Kursk city early on Wednesday and that they were most likely the sounds of air defence systems firing.

He later said that a Ukrainian unmanned aerial vehicle was intercepted in the sky over Kursk region, adding that there were no casualties or damage.

In Voronezh, the administrative centre of another southern province, TASS news agency cited an emergencies ministry official as saying that two blasts had been heard and the authorities were investigating.

Regional governor Alexander Gusev said in the morning that an air defence system had detected and destroyed a small reconnaissance drone.

Russia said it was sending investigators to Kursk and Voronezh regions to document what it calls “illegal actions by the Ukrainian army”.

Mr Podolyak said it was not possible to “sit out” the Russian invasion.

“And therefore, the disarmament of the Belgorod and Voronezh killers’ warehouses is an absolutely natural process. Karma is a cruel thing,” he said.

Surprising prisoner swap

Russia and the United States have carried out a long-discussed prisoner swap but one that still came as a surprise.

Russia released American citizen Trevor Reed and received Konstantin Yaroshenko, convicted in the US, in exchange.

US President Joe Biden confirmed Reed’s release in Washington DC.

Mr Biden and his Russian counterpart Vladimir Putin had discussed the exchange at their summit meeting in Geneva last year.

In view of the tense relations between the two countries, drastically exacerbated by the Ukraine war, this development is unexpected.

The US had repeatedly demanded the release of the 30-year-old Reed.

In July 2020, he was sentenced to nine years in a prison camp for allegedly assaulting police officers and resisting Russian authorities while drunk.

Tweet from @Reuters

The US ambassador to Russia, John Sullivan, had criticised the sentence as absurd theatre.

Reed’s family had also lobbied the US government to do everything possible to secure the former US Marine’s release.

Russian pilot Yaroshenko had been sentenced to 20 years in prison for drug smuggling in the US in 2010.

Russia had proposed a prisoner swap for Yaroshenko in July 2019 in exchange for the release of any US citizen.

Yaroshenko is a pilot convicted of conspiracy to smuggle cocaine into the country.

He was arrested by US special forces in Liberia in 2010.

“Today, we welcome home Trevor Reed and celebrate his return to the family that missed him dearly,” Mr Biden said.

He said the former US soldier was no longer in Russian custody.

He did not provide more specific details.

Mr Biden thanked Mr Sullivan and other US government officials for their efforts to secure Reed’s release.

The negotiations had required “difficult decisions,” he stressed.

“His safe return is a testament to the priority my administration places on bringing home Americans held hostage and wrongfully detained abroad,” he said.

Indonesia invites Ukraine to G20 summit

Ukraine’s President Volodymyr Zelenskiy says his Indonesian counterpart has invited him to attend the G20 summit to be held in the Southeast Asian country later this year.

“Had talks with President @jokowi…Appreciate inviting me to the @g20org summit,” he said in a tweet, referring to Indonesia President Joko Widodo, the current G20 chair, by his nickname.

Indonesia’s presidential palace and state secretary’s office did not immediately respond to requests for comment.

Ukraine is not a member of the G20 but the chairs of the grouping have previously invited countries as guests to join meetings.

Indonesian foreign ministry spokesman Teuku Faizasyah did not immediately confirm Zelenskiy’s invitation when contacted by Reuters but said the foreign minister had been “in consultations” and reported the results to Jokowi.

He did not specify who the consultations were with.

The G20 has condemned Russia’s invasion of Ukraine, which, now in its ninth week, has raised geopolitical tensions, sent shockwaves through the global economy and sparked a humanitarian crisis.

Russia calls its actions in Ukraine a special operation.

Several G20 members have called for Russia and its President Vladimir Putin to be excluded from the leaders summit in Bali in November but Indonesia has demurred, saying it is too early to decide.

At a meeting of G20 finance officials in Washington DC last week, delegates from the US, Britain and Canada walked out on Russia’s delegates.

Indonesian Finance Minister Sri Mulyani Idrawati acknowledged the body faced unprecedented challenges but called for co-operation to overcome headwinds slowing global growth.

-with AAP