Ukraine launched a massive cyber attack on Russian airports and airlines, bringing flights to a virtual standstill across the capital Moscow and other parts of the country.

The bold attack came as Russians prepared to celebrate Independence Day on June 12, an annual holiday held every year since 2002.

FSB officials said there had been a “massive” failure to online resources for Russian airlines and airports.

For over fifteen hours, websites belonging to Moscow’s Domodedovo airport and the airline companies Nordwind, S7 and the national carrier Rossiya were inaccessible.

Russia’s cyber crimes unit GOSSOPKA said the attacks were ongoing and continued to cause significant problems.

Ukraine’s military intelligence agency the GUR admitted being behind the disruption.

“Attacks are being carried out on the resources of Domodedovo Airport, Gagarin Airport in Saratov, and the airport in Yuzhno-Sakhalinsk,” an agency’s source told the website ukrinform.net.

“As a result of the attack, flights are being delayed. In particular, passengers cannot fly out to Sochi, Bodrum, and Moscow.

“Planes are diverted to reserve airfields in Samara or Ulyanovsk.”

Ukrainian hackers also gained access to the official website of the regional parliament of Stavropol in southern Russia.

They placed a banner depicting Red Square with Ukrainian flags and the inscription “Hold on, we will liberate you!” The server was later taken down.

In addition, they attacked the servers of the upper chamber of Russia’s parliament, as well as those of several otherRussian government agencies.

The GUR source said: “The so-called Russia Day continues. Putin’s subordinates will have many more such ‘gifts’.”

Earlier in June the GUR targeted large Russian companies and state institutions in large-scale DDoS attack.

Websites belonging to several key ministries such as defence and finance were brought down.