LONDON — The pilot of a Ryanair flight that was diverted to Belarus last month, leading to the arrest of a dissident Belarusian journalist, had no alternative but to land the plane in Minsk, the head of the budget airline said Tuesday. 

Ryanair CEO Michael O'Leary appeared before a British Parliament committee to give evidence on the May 23 diversion. The scheduled flight from Greece to Lithuania changed course and landed in Belarus' capital. Opposition journalist Raman Pratasevich, who had been a passenger on the plane, was arrested. 

O'Leary told British lawmakers that Minsk air traffic control warned the flight crew of a "credible threat" that if the plane entered Lithuanian airspace, "a bomb on board would be detonated." 

The captain repeatedly asked to communicate with Ryanair's operations control center, but Minsk air traffic officials told him — falsely — that "Ryanair weren't answering the phone," O'Leary said. 

"This was clearly a premeditated breach of all the international aviation rules, regulations, safety," he said.

O'Leary said the pilot was put under "considerable pressure" to land in Belarus instead of the more standard options of Poland or other Baltic countries. 

"He wasn't instructed to do so, but he wasn't left with any great alternatives," he told embers of the Parliament committee. 

After the plane was on the ground, several "unidentified persons" boarded the aircraft with video cameras, according to O'Leary.

They "repeatedly attempted to get the crew to confirm on video that they had voluntarily diverted to Minsk," the Ryanair executive said. The crew refused to provide such confirmation, he said. 

Western countries have called the forced diversion a brazen "hijacking" by Belarus. Outraged European Union leaders swiftly slapped sanctions on the country, including banning Belarusian airlines from using the airspace and airports of the 27-nation bloc and telling European airlines to skirt Belarus. U.K. authorities took similar actions. 

O'Leary said he did not support continuing such flight bans in the long term. 

"We cannot have a situation whereby airlines, air travel, our customers and our citizens run the risk of being hijacked and diverted under false pretenses," he said. "But equally, far more U.K. citizens will be disrupted as a result of long-haul flights between the U.K. and Asia, for example, now having to fly around Belarus or avoiding Belarusian airspace."