MOSCOW (Reuters) -Russian airline Aeroflot was forced to cancel more than 50 round-trip flights on Monday, disrupting travel across the world's biggest country, as two pro-Ukraine hacking groups claimed to have inflicted a crippling cyberattack.

A cyberattack on Russian airline Aeroflot has caused a major outage, leading to over 100 flight cancellations and delays.

Russian prosecutor said it opened a criminal investigation into the cyberattack targeting Aeroflot, the largest airline in Russia.