Food, water and medical help are in short supply at camps in western Myanmar that are "stretched beyond capacity", a UN agency said Tuesday, as authorities struggled to stem communal clashes.
Bloodshed between Buddhists and Muslims in Rakhine state has caused more than 28,000 people to flee their homes this month, the United Nations refugee agency said in a statement.
"It is clearly urgent that law and order be restored to prevent further violence, and that access is facilitated so that aid can be provided to those in need," the agency said.
The ongoing fighting, which erupted on October 21 and killed dozens, has seen whole neighbourhoods razed in a spate of arson attacks that United Nations staff said had resulted in "widespread destruction and displacement".
Thousands from mainly Muslim communities in Rakhine state have streamed towards camps already struggling to cope with the 75,000 people displaced by earlier clashes in June.
"With the new influx, these already overcrowded camps are being stretched beyond capacity in terms of space, shelter and basic supplies such as food and water," UNHCR said.
"Food prices in the area have doubled and there are not enough doctors to treat the sick and wounded."
Authorities have struggled to end the violence.
Police shot and killed one ethnic Rakhine during renewed clashes on Tuesday, a government official told AFP, declining to be named. The death brings the toll from the latest unrest to 89.
"Thousands of people were there. We do not know yet whether the tension has been eased now because communication and transportation is very difficult," he said of the fighting in Kyaukpyu, one of several violence-hit townships.
UNHCR said more than 3,000 people have travelled in boats towards the state capital Sittwe in hopes of finding shelter at the camps on the coast near the outskirts of the city.
Many are now living on the barren shoreline, according to an AFP reporter who visited the scene.
"We have no home, no place to stay, no money -- that's how it is. The children are hungry from when the day starts and they cry," said Ahpu, who was separated from her husband and son as she ran for her life.
The 42-year-old, who gave only one name, told AFP the attack on her village in Kyaukpyu was instigated by ethnic Rakhine Buddhists, with whom her Kaman Muslim community had lived "like family" in the past.
Human Rights Watch on Saturday released satellite images showing what it said was destruction of Kyaukpyu -- a mainly Rohingya Muslim area and the site of a major pipeline taking gas to China -- where virtually all structures appear to have been wiped from the landscape.
Decades-old animosity between Buddhists and minority Rohingya Muslims exploded in June after the apparent rape and murder of an ethnic Rakhine woman sparked a series of revenge attacks.
Myanmar's 800,000 stateless Rohingya, viewed by the United Nations as among the most persecuted minorities on the planet, are seen by the government and many Burmese as illegal immigrants from neighbouring Bangladesh.
But other Muslims in Rakhine have also been swept up in the latest violence, including the Kaman, one of Myanmar's officially recognised ethnic groups.
UNHCR raised concerns about reaching the displaced in "extremely hard-to-reach areas", and said unknown numbers had fled into the hills.
The agency said another 6,000 people were stranded on boats or on islets along Myanmar's west coast and "are looking for safe access to places where they can receive assistance".
Rakhine government spokesman Win Myaing indicated that the unrest could continue to flare.
"Some ask me how long the clashes will continue. We do not know. It could go on for about a month or two. It could even be as long as a year or two," he told AFP.
Myanmar has rejected an offer by the Association of Southeast Asian Nations to open talks aimed at quelling the conflict, the bloc's Secretary-General Surin Pitsuwan told reporters in Malaysia.
Late Tuesday a Bangladeshi border guard commander told AFP more than 160 Rohingya Muslims fleeing Rakhine state had been "pushed back" since the latest wave of violence erupted.
Bangladesh has said it will not accept any new refugees from Myanmar as it is already burdened with an estimated 300,000 Rohingya living in its southeast -- a stance criticised by the United Nations and rights groups.