Russian troops stationed in Kyrgyzstan as security for Russia's Kant military base will not be used to restore order in the southern part of the Central Asian state, a senior military official said Saturday.

"These military units have a strict mission, and they will not be used for other purposes," said the source as quoted by the Itar-Tass news agency.

Earlier, Kyrgyz interim leader Roza Otunbayeva appealed for Russian military support to maintain order in the south of the country.

After talking with Russian Prime Minister Vladimir Putin by phone late Friday night, Otunbayeva told reporters Saturday a written appeal had been sent to Russian President Dmitry Medvedev.

"Since yesterday evening the situation has gone over the edge, we need the input of other military forces to stop the situation. In this concern, we appealed for help to Russia," the interim leader said.

Medvedev said Friday that Russia was ready to assist if necessary.

"I believe all the existing problems will be resolved by the Kyrgyz authorities. The Russian Federation will help," he said.

However, troops from the post-soviet security bloc, the Collective Security Treaty Organization (CSTO) would not enter Kyrgyzstan, Medvedev said.

That could only happen if one of the block -- Kyrgyzstan, Russia, Armenia, Belarus, Kazakhstan, Uzbekistan and Tajikistan -- was attacked by a foreign state, the Russian president said.

Medvedev said in the Uzbek capital of Tashkent Friday the Shanghai Cooperation Organization (SCO) would send observers to Kyrgyzstan, which he regarded as an "ally and a close partner".

Following the eruption of violence, Russian and Kyrgyz airlines have cancelled flights between Moscow and Osh, the second largest city of Kyrgyzstan where the unrest originated due to inter-ethnic clashes.

Moscow police also beefed up security around the Kyrgyz and Uzbek embassies to Russia.

The death toll has risen to 63 with another 838 injured.

The current clashes followed violence in May when supporters of former President Kurmanbek Bakiyev clashed with supporters of the interim government in the southern cities of Osh and Jalalabad.

Bakiyev was ousted in April when riots broke out across the country. At least 85 people were killed and thousands of others injured in those clashes.

Kyrgyzstan is expected to vote on a new constitution later this month, followed by new parliamentary elections in October.