A number of people due to attend an HIV/AIDS conference in Australia were onboard the doomed flight MH17 when it was shot down over eastern Ukraine, according to reports.

The plane, which was flying from Amsterdam to Kuala Lumpur, was a connecting flight for many people heading to the International AIDS Conference in Melbourne, which was due to start this weekend.

Organisers confirmed to the Sydney Morning Herald that expected conference attendees were among those thought to have died in the crash, with the newspaper reporting that ‘about 100′ attendees were among the 298 onboard the flight.

International AIDS Society spokesperson Michael Kessler said: “A number of colleagues and friends en route to attend the 20th International AIDS Conference taking place in Melbourne, Australia, were on board the Malaysia Airlines MH17 flight that has crashed over Ukraine.”

“At this incredibly sad and sensitive time the IAS stands with our international family and sends condolences to the loved ones of those who have been lost to this tragedy.”

Renowned Dutch HIV researcher Dr Joep Lang, AIDS campaigner Pim de Kuijer, and WHO member Glenn Thomas are among those reported to have been onboard. Tributes to the researchers have been paid across the internet.

Terrence Higgins Trust tweeted: “Stunned by reports that #AIDS2014 delegates inc leading researcher Joep Lange were on #MH17. Terrible news for #HIV community.”

The National AIDS Trust added: “Reports Joep Lange died in Malaysian plane crash today, with other scientists on way to @AIDS_conference. Desperately sad news.”

The plane was carrying 173 Dutch nationals, 27 Australians, 44 Malaysians (including 15 crew), 12 Indonesians and nine Britons.

Ukraine has set up a no-fly zone following the incident, and international investigators are currently looking into the cause of the crash.