Bishkek: Kyrgyz troops and police were patrolling hot-spots in the south of the country on Sunday with a green light from the interim government to shoot to kill to quell continuing ethnic unrest.
A government decree issued on Saturday said lethal force would be authorised to repel attacks against the authorities, stop the destruction of government and private property and protect civilians.
"The violence, the number of pillages and massacres are growing...," said the decree.
"If we do not take opportune and effective measures the unrest could become much more serious and descend into a regional conflict."
Ethnic rioting spread today in southern Kyrgyzstan, where at least 80 people have been killed and more than 1,000 wounded.
Thousands of Uzbeks fled after their homes were torched by roving mobs of Kyrgyz men.
Interim President Roza Otunbayeva earlier appealed to Moscow to intervene militarily.
"Since yesterday the situation has got out of control," said Otunbayeva in a nationally televised address.
"We need outside military forces to halt the situation. For this reason we have appealed to Russia for help."
But while Moscow said it was rushing humanitarian aid to the Central Asian former Soviet republic, a spokeswoman for President Dmitry Medvedev said it would not yet send troops, Russian news agencies reported.
"This is an internal conflict and Russia does not yet see the conditions for its participating in resolving it," Natalya Timakhova said.
A decision to dispatch peacekeepers could be taken only after consultations with the United Nations, she added.
The provisional government has struggled to impose order in the Central Asian state since seizing control during riots that ousted President Kurmanbek Bakiyev in April.
The authorities on Saturday declared a second state of emergency in the southern city of Jalalabad.
Deputy Interim Minister Azimbek Beknadzarov said on national television that this had become necessary because the instability was spreading.
The violence first erupted in the Osh region late Thursday when brawls between ethnic Kyrgyz and ethnic Uzbeks escalated into running street battles, prompting the government to impose a curfew and state of emergency.
Cars were smashed and burned, and buildings set on fire, in the city, which was once the stronghold of Bakiyev.
The European Commission on Saturday announced that it would send an humanitarian expert to evaluate the situation and determine what aid was needed.
Uzbekistan itself meanwhile voiced "extreme alarm" on Saturday at the violence, calling it an organized bid to inflame ethnic tensions.