Kyrgyzstan's interim government on Saturday appealed to retired police and army officers to travel to the southern city of Osh to prevent ethnic clashes there escalating into civil war.
"The provisional Kyrgyz government calls on retired police and military officers to contribute to the stabilisation of the situation in Osh," said government spokesman Azimbek Beknazarov, the 24.kg news agency reported.
"The authorities will be grateful for any volunteers who are ready to help prevent civil war in the south of Kyrgyzstan," he added.
Beknazarov was speaking from the region where clashes between ethnic Kyrgyz and ethnic Uzbeks broke out late Thursday.
The appeal came as the health ministry issued an updated death toll from the violence, saying at least 49 people had been killed and 650 injured in the clashes. The previous death toll had stood at 45.
Beknazarov said the situation there remained "very difficult" despite the state of emergency declared by the government and the 8:00 pm to 6:00 am (1400 GMT to 0000 GMT) curfew on Osh and neighbouring districts.
"Exchanges of fire are continuing and you can hear them everywhere, several buildings are in flames, people are frightened," he said.
Police officers and soldiers deployed to the troubled zone were exhausted, falling asleep on the roads they were meant to be watching, he added.
"We won't have enough people on the ground to ensure security over the next two days, if we don't get more help," he warned.
The violence, thought to have been set off by a brawl between youths from the different ethnic groups late Thursday, quickly escalated into street battles in which people fought using improvised weapons but also firearms.
It comes some two weeks before a referendum on the constitution, scheduled for June 27.
Since last April's uprising, which ousted Bakiyev and left 87 people dead, foreign leaders have warned of the danger of civil war in this strategically important country.