John Bacon

USA TODAY

Malaysian authorities on Sunday marked the 100th day since Malaysia Airlines Flight 370 vanished by promising to continue searching for the jet and the 239 people who were on board it.

"This search effort is unprecedented in sheer scale and complexity," Transport Minister Hishammuddin Hussein said in a statement. "We reaffirm our commitment with renewed vigor to locate the missing MH370.

"We will, with the grace of God, find this missing plane and so with it begins the process of healing."

Family members of some of the people aboard the flight gathered in the Malaysian capital of Kuala Lumpur for a small ceremony marking 100 days.

The Beijing-bound flight disappeared off radar screens March 8, shortly after takeoff from Kuala Lumpur. The search for the doomed airliner has focused on a massive swath of the Indian Ocean some 1,000 miles off Australia's coast, but no trace has been found.

About 10 days ago the search target area was moved to a new section of the ocean following new analysis of satellite communications, Australian officials said.

Airline CEO Ahmad Jauhari also issued a statement Sunday, acknowledging that "Despite the best efforts and resources over the last 100 days, this most extensive search in history has still not found answers."

Thoughts and prayers are with the families, he said.

"We feel the families' pain; we miss our colleagues and friends on board MH370," the statement said. "We feel the families' anguish, and like them, Malaysia Airlines continues to hope and seek answers that will bring us closer to finding out what happened to MH370."

Two advocacy groups for the families of those on the plane, the MH370 Family Association and Voice 370, released a letter sent to Australian Prime Minister Tony Abbott and the head of the international search effort, Angus Houston, thanking the people involved in the search. The letter also singled out the efforts of China and the United States, but made no mention of Malaysia.