MOSCOW — The opposition movement leader in the mountainous enclave of South Ossetia had planned to be inaugurated as its rightful president on Friday in an unauthorized ceremony. Instead, she lay unconscious in a hospital with a possible rifle-butt blow to the head, her aides were under arrest and her organization was in disarray, crushed by police officers apparently acting on the Kremlin’s orders.

The crushing of the movement led by the would-be president, Alla A. Dzhioeva, on Thursday, came at a delicate moment as Russia has struggled to install its favored leaders in South Ossetia as well as in other former Soviet separatist regions that are its de facto protectorates.

Russian-backed candidates had recently lost elections in both South Ossetia and Abkhazia, which are the separatist regions in Georgia that were a cause of the war between Russia and Georgia in 2008. Another Russian-backed candidate was defeated in Transnistria, a breakaway territory in Moldova.

The Russians had harbored some hope in South Ossetia, but Ms. Dzhioeva unexpectedly defeated the Kremlin-backed candidate in November. In December, the region’s Supreme Court annulled the election results, citing campaign violations.