The Dutch prime minister on Thursday ordered that flags fly at half mast at government buildings across the country after the death of at least 189 of his country's citizens in what he said might be the worst air disaster in the Netherlands' history.
The Dutch were among 295 passengers and crew, including three infants, aboard a Malaysia Airlines Boeing 777 travelling from Amsterdam to Kuala Lumpur that crashed while crossing above the conflict zone in eastern Ukraine where pro-Russian rebels are fighting forces controlled by the government in the capital Kiev.
Speaking at Schiphol Airport after interrupting his holiday in southern Germany on news of the crash, Dutch Prime Minister Mark Rutte said it was a "black day" for the Netherlands.
"The whole of the Netherlands is in mourning," he said. "This beautiful summer day has ended in the blackest possible way."
Malaysia Airlines flight MH17, which was operating as a code-share flight with the Dutch flagship carrier KLM, was also carrying at least 27 Australians, 23 Malaysians, 11 Indonesians, six Britons, four Germans, four Belgians, three Filipinos and one Canadian.
The 15 flight crew — two captains, two flight officers and 11 cabin crew — were all Malaysian citizens. The nationalities of a further 47 were as yet unknown.
Malaysia Airlines' Europe vice president Huib Gorter told reporters that relatives would be provided with support if they requested it and could be flown from Amsterdam and Kuala Lumpur to Kiev if they so wished.
"You cannot imagine what's happening to these people right now," he said. "They are our main concern."
An influential Dutch AIDS expert was among the 298 passengers on the Malaysian airliner, along with others who were headed to an international AIDS conference in Melbourne, an Australian associate said on Friday.
Joep Lange, who spent more than 30 years researching and fighting HIV and AIDS, was known for advocating cheap access to treatments in poor countries.
"Joep had an absolute commitment to HIV treatment and care in Asia and Africa," said David Cooper, a professor at the Kirby Institute at the University of New South Wales, who worked closely with Lange on an HIV research project in Bangkok.
"The joy in collaborating with Joep was that he would always bring a fresh view, a unique take on things, and he never accepted that something was impossible to achieve," Cooper said in a statement.
The conference, due to start on Sunday in Melbourne, features former U.S. President Bill Clinton among its keynote speakers.
As many as 100 attendees were on the doomed flight, Fairfax Media reported, including Lange, a former president of the International AIDS Society which organizes the conference.
Lange, a professor of medicine at the Academic Medical Center at the University of Amsterdam, pioneered development of affordable combination therapies to treat HIV and simple antiretroviral drug treatments to prevent transmission of HIV from mothers to their babies in poor countries.
He was also scientific director of the Amsterdam Institute for Global Health and Development. Institute officials were not immediately available to comment.
Lange was traveling with his partner, Jacqueline, the Kirby Institute said.