MOSCOW — Unidentified assassins tried on Wednesday to kill the president of Abkhazia, a Russian-backed rebel enclave of Georgia. The assailants used automatic rifles, grenade launchers and a powerful roadside bomb in an attack that raised fresh questions about Moscow’s ability to preserve order there.

The president, Aleksandr Z. Ankvab, survived the attack without injury, but at least one bodyguard died and two more were seriously wounded. It was the sixth attempt on Mr. Ankvab’s life in less than a decade, a testament to the volatility of Abkhazia.

Reached by telephone at his office in Abkhazia’s capital, Mr. Ankvab’s voice was faint and shaky.

“I’m sorry, I can’t talk right now, especially about this topic,” he said about the assassination attempt.

The attack was likely to provoke new anxiety in Moscow, which has been struggling to put a damper on recent political tremors in Abkhazia and another breakaway Georgian enclave, South Ossetia. After its war with Georgia in 2008, Russia defied international condemnation and recognized both regions as independent states.