MOSCOW — Russia presented a combination of conciliation and bluster on Monday over its handling of the downed Malaysia Airlines jet, with President Vladimir V. Putin seemingly probing for a way out of the crisis without appearing to compromise with the West.

On one hand, he offered conciliatory words in a video statement, oddly released in the middle of the night, while the separatists allied with Moscow in southeastern Ukraine released the bodies of the victims and turned over the black box flight recorders from the doomed aircraft to Malaysian officials.

However, two senior military officers forcefully demanded that the United States show publicly any proof that rebels fired the fatal missile, and again suggested that the Ukrainian military shot down the Malaysia Airlines jet despite the fact that Ukraine has not used antiaircraft weapons in the fight along its eastern border.

Mr. Putin seemed to respond to the outraged international demands growing daily that he intervene personally to rein in the rebels — particularly to halt the degrading chaos surrounding the recovery of the remains. But at the same time, Moscow did not concede that it was at fault.