MOSCOW, Russia - June 13, 2010 - In a desperate bid to stop the spread of ethnic violence in southern Kyrgyzstan, the interim government Sunday mobilized hundreds of reservist troops and issued a decree authorizing soldiers to shoot to kill rioters.

The move came after Moscow denied a request Saturday by interim President Roza Otunbayeva to send in Russian troops to quash the ethnic riots in the former Soviet republic.

More than 100 people have been killed in three days of fighting that began with clashes between the Kyrgyz and Uzbek ethnic groups in the city of Osh and has since spread to other areas of the south, including Jalal-Abad, according to news reports and officials. About 1,200 people have been injured.

An estimated 75,000 Uzbeks have fled across the border into neighboring Uzbekistan, an unnamed official with that nation's Emergency Ministry told RIA Novosti news agency Sunday. A majority of them were women, children and injured persons, the official said.

The plea for help from Russia was unusual for Kyrgyzstan, which gained its independence from Moscow with the breakup of the Soviet Union in 1991. Kyrgyzstan has been ruled by an interim government and plagued by occasional violence since a coup in April ousted President Kurmanbek Bakiyev.

Though Russia has said it will not intervene in what it called an internal Kyrgyzstan matter, it has sent additional troops to beef up security at a military base it maintains in northern Kyrgyzstan, Natalia Timakova, press secretary for Russian President Dmitry Medvedev, confirmed.

Earlier, a Russian defense source speaking on condition of anonymity had said that three Ilyushin Il-76 military transport planes carrying a battalion of troops had flown to the Russian military base near the northern Kyrgyzstan city of Kant, far from the rioting, to provide extra security at the facility.

The United States also maintains an air base in northern Kyrgyzstan that is used for resupplying Western troops in Afghanistan.