Pregnant women and children urgently need medical treatment and food as hundreds of thousands flee ethnic fighting in Kyrgyzstan, say aid workers.
But the central Asian republic’s security situation has meant aid organisations have not been able to get to people in need.
"People are desperate to escape the violence but without assistance there's no way out and every minute of delay is costing lives," said Human Rights Watch’s Andrea Berg.
"Kyrgyz authorities need to set up effective measures to protect people and negotiate safe access for those who want to flee," she told Radio France Internationale.
The Red Cross has warned of a humanitarian crisis as at least 75,000 ethnic Uzbeks have fled the fighting which last night threatened to escalate into a full-blown civil war and even conflict between Kyrgyzstan and Uzbekistan.
Aid organisations appealed to the neighbouring Uzbek government to keep its borders open and allow people seeking protection entry into the country. But Uzbekistan yesterday closed its border with the former Soviet state, saying it cannot cope with any more refugees.
At least 124 people have been killed and more than 1,685 wounded in street battles between ethnic Kyrgyz and Uzbeks in the Jalalabad and Osh regions that have raged since Thursday.
“There has been no water or gas for four days. People are running out of food,” said William Lynch, Save the Children’s Kyrgyzstan Country Director. “There was one small food distribution of 1 kg of potatoes per family Saturday in Osh by the military,” he told Channel 4 news.
“People are staying in groups of families and neighbours. Temperatures are in the 80s and living conditions are dire. Bodies are left unburied in the streets.
Teams from the International Committee of the Red Cross were trying to treat the wounded, but armed checkpoints were standing in their way, said spokesman Marcel Izard.
“What we are really worried and concerned about are credible reports that ambulances have not been let through at times,” Izard said.
“There are many checkpoints will heavily armed men, so even making it through ourselves, it is too dangerous to go to the southern parts of Kyrgyzstan.
“In Osh … our colleagues believe many inhabitants are still hiding in their houses, too afraid to come out.”
Tensions between ethnic Kyrgs and Uzbeks have risen since former president Kurmanbek Bakiyev was ousted in April. UK foreign affairs chief Catherine Ashton says she is "very concerned" at the unrest and called for moves to form a stable government.