Crew members of a Cathay Pacific passenger flight had reportedly witnessed the North Korean Hwasong-15 missile blowing up and falling apart when the reclusive nation launched the intercontinental ballistic missile (ICBM) on Wednesday, 29 November.

The airlines confirmed that crew of the CX893 flight has reported the suspected sighting of the missile — which Pyongyang said can hit targets "everywhere in the world" — when they were mid-flight. The passenger aircraft was flying from San Francisco to Hong Kong.

The operators insist the missile flew far from the flight's path and at no point posed a threat to the aircraft. The Hong Kong-headquartered Cathay Pacific, which is considered one of the safest airlines in the country, said it has no plans of rerouting any of its flights.

"Though the flight was far from the event location, the crew advised Japan ATC [air traffic control] according to [the] procedure," said a spokeswoman for the airline. The flight was cruising over Japan when the North Korean missile was launched. The flight crew reported the incident about the suspected sighting at 2.18am Hong Kong time meaning the pilots could have watched the re-entry of the missile into the atmosphere.

North Korea, which has access to civil aviation data, does not usually inform other nations about any missile launch and this could be a potential risk to aircraft flying in the region. The latest North Korean missile, said to be the most-powerful projectile as yet, flew about 950km before plunging into the waters of the Sea of Japan.

In a leaked internal memo, the airline's general manager for operations, Mark Hoey, told the staff, "Today [date unspecified] the crew of CX893 reported, 'Be advised, we witnessed the DPRK missile blow up and fall apart near our current location.'" The Democratic People's Republic of Korea or DPRK, is the official name for North Korea.

"We advised ATC [air traffic control] and ops [operations] normal. Looking at the actual plots, CX096 might have been the closest, at a few hundred miles laterally," added Hoey referring to a Cathay Pacific cargo flight, CX096, flying in the same region.

Following the incident, several Hong Kong media outlets reported satellite phones have been distributed to crews operating flights in the region — this is to ensure emergency communication if the normal channels become dysfunctional.