Makhachkala, Russia, 13 August 1999 (RFE/RL) - Moscow says a massive military operation is to begin soon to crush separatist Islamist rebels in Russia's Caucasus republic of Dagestan. Russian military officials said troops and supplies were being airlifted to the region in preparation for an offensive aimed at routing the rebels quickly. The military said yesterday it had flown more than 200 sorties since the fighting began six days ago. It said it had so far lost three helicopters and that 10 soldiers have been killed. The Russian Interior Ministry said 150 rebels had been killed so far. The rebels, who have seized a number of Dagestani villages, say they have lost only five fighters. Moscow appealed to moderate leaders of the neighboring breakaway republic of Chechnya to help in the fight against the rebels, who seek to unite Dagestan and Chechnya in an Islamic state. No response from the Grozny leadership--which claims independence from Russia--was immediately available.