MOSCOW — Islam Karimov, a ruthless autocrat who ruled Uzbekistan for almost three decades, died on Friday in the Uzbek capital, Tashkent. He was 78.

A joint statement by the cabinet of ministers and Parliament announced the death, saying he had a stroke that led to multiple organ failure.

The announcement followed a long, strange interlude during which Uzbek officials refrained from confirming the death even while the leaders of Turkey and Georgia expressed condolences, mosque leaders were barred from offering prayers for the president’s health, and funeral arrangements were being made very publicly. A respected opposition website posted pictures of cemetery workers in Samarkand, the president’s hometown, digging a fresh grave in a prominent location.

The likeliest reason for the official silence was that top government officials had been unable to decide on the succession and did not want to announce that Mr. Karimov was dead until they could also say who would replace him, at least temporarily.