At least six delegates to The 20th International AIDS Conference (AIDS 2014) in Melbourne, Australia, were among the passengers aboard the Malaysia Airlines flight that crashed in eastern Ukraine on Thursday, killing all 298 onboard.

The conference is going on as scheduled, July 20–25, at the Melbourne Convention and Exhibition Centre, according to a statement on the International AIDS Society’s Web site. The president of the Society, Francoise Barre-Sinoussi, opened the conference Sunday by asking past presidents and the incoming president to join her onstage. “The extent of our loss is hard to comprehend or express,” said Barré-Sinoussi. “We grieve alongside all of those throughout the world who have lost friends and family in this senseless tragedy.”

They asked for a moment of silence to represent “our sadness, our anger, and our solidarity,” added Dr. Daniel Kuritzkes, chief of the division of infectious diseases at Brigham and Women’s Hospital, who is attending the conference, according to a Boston Globe report.

Former International AIDS Society president Joep Lange was a passenger on the plane as was Glenn Thomas of the World Health Organization.

Industry Reacts

The president of the International Congress and Convention Association, Arnaldo Nardone, wrote a message to the association’s members expressing sadness that “such dedicated people from many countries, traveling to be with friends and strangers to find solutions to extraordinarily complex problems, [had] their lives cut short by the violent actions of individuals who refuse to negotiate, compromise, or even try to understand each other, even though they are neighbors.

“It is right that ICCA members and civilized people all over the world condemn utterly this awful act, and that we call on all parties in the Ukrainian conflict to meet together and commit to find a lasting, peaceful solution to the conflict. They owe this to the innocent victims of MH17.”

Condolence books are circulating on site at the conference for the duration of the event. A Candelight Vigil is scheduled at Federation Square in Melbourne on Tuesday evening.