Hungarian authorities have detained seven Ukrainian citizens, including a former Ukrainian intelligence officer, and seized two armored cars carrying large amounts of cash across Hungary on suspicion of money laundering, officials said Friday.

Ukraine accused Hungary of taking the Ukrainians hostage and illegally seizing millions of dollars in cash.

“This is state terrorism and racketeering,” Ukraine's Foreign Minister Andrii Sybiha wrote on X late Thursday.

The seven were employees of the Ukrainian state-owned Oschadbank, and they were traveling in two armored cars that were carrying the money between Austria and Ukraine when they were detained, Sybiha said.

The armored cars were carrying cash as part of regular services between state banks, he said, adding that the status of the employees was unknown.

In a separate statement, Oschadbank wrote that 40 million U.S. dollars as well as 35 million euros and 9 kilograms (19.8 pounds) of gold — worth around $1.5 million at current prices — had been apprehended by Hungary.

Hungary’s National Tax and Customs Administration confirmed Friday that it had detained seven Ukrainian citizens and seized the two armored cash-transport vehicles. It added it was conducting criminal proceedings on suspicion of money laundering.

Hungary’s Interior Ministry, Foreign Ministry and Counter-Terrorism Centre did not immediately respond to requests for comment.

GPS data showed the vehicles were in the center of Budapest near one of Hungary's law enforcement agencies, but that the location of the bank employees remained unknown, the Ukrainian bank said.

The incident further inflamed tensions between Hungary and Ukraine, which are embroiled in a bitter feud over Hungary's access to Russian oil through a pipeline that crosses Ukrainian territory.

Oil shipments through the Druzhba pipeline have been interrupted since Jan. 27. Ukraine says a Russian drone strike damaged the pipeline's infrastructure, and that repairing it carried risks to technicians. It said that even if restored, it would remain vulnerable to further Russian attacks.

Hungary's government, however, has accused Ukraine of deliberately holding up supplies of Russian crude, and has vowed to take countermeasures against Kyiv until oil flows resume.

Hungarian Prime Minister Viktor Orb n, who has maintained close relations with the Kremlin while escalating an aggressive anti-Ukraine campaign ahead of crucial elections next month, has called Ukraine Hungary's “enemy,” and accused Ukrainian President Volodymyr Zelenskyy of seeking to provoke an energy crisis in order to sway the April 12 vote.

Orb n did not directly mention the detention of the bank vehicles but alluded to the incident in statements to state radio Friday, saying: “We will stop things that are important to Ukraine passing through Hungary until we get the approval of the Ukrainians for oil shipments.”

“The Ukrainians will run out of money sooner than we will run out of oil,” he added.

Trailing in most polls behind a popular center-right challenger, the populist Orb n has staked the election on convincing voters that Ukraine poses an existential threat to Hungary's security.

In office since 2010, the EU's longest-serving leader has claimed that if he loses the election, the European Union will force Hungary into bankruptcy by cutting Russian energy imports, and that Hungarian youth will be sent to their deaths on the front lines in Ukraine.

Hungary, along with neighboring Slovakia, have defied EU efforts to wean off Russian fossil fuels, and continued to purchase them despite Moscow's invasion of Ukraine.

Orb n previously ceased diesel shipments to Ukraine, vetoed a new round of EU sanctions against Russia and blocked a major, 90-billion-euro ($106-billion) loan for Kyiv in retaliation for the interruption in oil shipments. He's also deployed military forces to key energy infrastructure sites across Hungary, accusing Ukraine of plotting disruptions.

On Thursday, Orb n told an economic forum that Hungary would use “force,” including “political and financial tools,” to compel Ukraine to resume oil shipments.

On his post on X, the Ukrainian foreign minister took issue with Orb n's comments, writing: “If this is the ‘force’ announced earlier today by Mr. Orban, then this is a force of a criminal gang,” Sybiha wrote.

Ukraine’s Foreign Ministry on Friday urged Ukrainian citizens to abstain from visiting Hungary, saying their security could not be guaranteed amid “arbitrary actions by the Hungarian authorities.”

The Ministry also called for Ukrainian and European businesses to take into account “the risk of arbitrary seizure of property” in Hungary.