Two Newcastle United fans travelling to watch their team play in a pre-season tour of New Zealand were on board the Malaysia Airlines flight MH17 which crashed in Ukraine.
John Alder, who was in his 60s and from Gateshead, had reportedly missed only one Newcastle game since 1973.
Liam Sweeney, aged 28 and from Newcastle, had also boarded the flight destined for Kuala Lumpur.
Newcastle are due to play two fixtures in the New Zealand cities of Dunedin and Wellington next week.
Tim Krul, the club's Dutch goalkeeper, tweeted:
A tweet from the official club account said:
Newcastle United managing director Lee Charnley said:
The loss of John and Liam is truly devastating news.
We're desperately sad to report that they were John Alder and Liam Sweeney. Both were well known to away followers, particularly John, whose usual matchday attire led to the affectionate nickname of "The Undertaker". Both were in attendance at Oldham on Tuesday, doing what they loved. Our thoughts are with their friends, families and the many fans who knew them by sight. Watching Newcastle will never be the same again.
A memorial image posted on Twitter by the fan account @gallowgateshots was retweeted hundreds of times.
Other fans paid tribute to their friends:
Fans of Sunderland, Newcastle's bitter local rivals, said
Nine Britons are thought to have died in the crash, which has killed more than 300 people.