* Uneasy calm in villages and capital of Rakhine state
* Aid slowly arriving for thousands of displaced
* Violence could easily reignite when villagers return (Adds details)
BYAING PHYU, Myanmar, June 16 (Reuters) - Deep-seated anger and fear smoulder between Rohingya Muslims and ethnic Rakhine Buddhists in the aftermath of the worst sectarian clashes in Myanmar in years, raising concerns that a fragile peace may not last long.
Violence has largely subsided in northwestern Rakhine state, leaving reformist President Thein Sein with the difficult task of averting another round of mob attacks that have left dozens dead and tens of thousands homeless.
"The government should separate Rakhines and Rohingyas because we can no longer live together," Than Mya, a 30-year-old mother of five who lost her husband, told Reuters on Saturday at a camp for displaced villagers in Rakhine's capital, Sittwe.
"My husband was at the front when the fighting started. I didn't see him die," she said, while kneeling on the ground with a huge statue of Buddha behind her.
The official death toll from two weeks of attacks stands at 50, with 58 injured and more than 2,500 houses burned down, according to state media. Local people say many more died.
More than 200 people remained missing from the Muslim town of Maungdaw, where the unrest first started eight days ago, said an official recording casualties for the government, requesting anonymity because he was not authorised to speak to the media.
What started the rampage of rock-hurling, arson and machete attacks is unclear and the subject of heated debate in Myanmar, where there is entrenched, long-standing animosity towards the stateless Rohingyas, of whom there are an estimated 800,000, most living in abject conditions.
Relations between Buddhist Rakhines and the Rohingyas, who are recognised by neither Myanmar nor neighbouring Bangladesh, have always been uneasy and tension flared last month after the gang rape and murder of a Buddhist woman that was blamed on Muslims. That led to the killing of 10 Muslims in reprisal on June 3 by a Buddhist mob.
The violence is a major setback for a rapidly reforming Myanmar that has seen a year of dramatic political change after 49 years of oppressive military rule. Opposition leader Aung San Suu Kyi, on her first visit to Europe in nearly a quarter of a century, has called for calm.
The 15-month-old government has made peace and unity in what is one of Asia's most ethnically and religiously diverse nations a central part of a reform agenda it says is "irreversible".
The quasi-civilian administration is being urged by rights groups and Western countries to treat the Rohingyas fairly and humanely, but anything more than that, such as granting them citizenship, risks angering many Burmese, who sees the Rohingya issue as one of national sovereignty.
Food aid was slowly trickling in to the dozens of camps, mainly monasteries and schools, housing more than 30,000 displaced Rohingyas and Rakhines.
One Sittwe camp visited by Reuters journalists found more than a thousand Rakhine women, children and elderly villagers packed inside a monastery awaiting their twice-daily ration of rice, fruit and rain water.
"They are getting enough food but the security around here is not good. The men have stayed in the villages to protect their houses, so we are left with little security," said Sa Kin Da, a Buddhist monk at the camp.
Further down the road, firemen hosed down smoke still billowing from a deserted Rohingya house.
Thousands of Rohingyas have fled Sittwe while some were adrift in boats on the Naf River between Myanmar and Bangladesh, the United Nations said. Bangladesh has repelled at least a dozen boats this week.
"I don't want to live here in Rakhine state anymore. I have eight family members and three have died already, " said one Rohingya in the camp, Maung Maung.
Reuters journalists visited the deserted Narzi quarter in Sittwe, which was home to as many as 10,000 Rohingyas, and found hundreds of houses, shops and market stalls destroyed by fire. Teams of Red Cross helpers and emergency volunteers cleared the wreckage as armed soldiers and police looked on.
Dozens of rioters have been arrested and paraded on television with seized bottles of petrol, knives and spears.
Violence could easily reignite once the thousands of displaced Rakhines and Rohingyas return to their battered villages and wrecked homes. The army and police do not appear to have the capacity to patrol all the potential flashpoints, focusing their limited resources mainly on Sittwe.
"(Rohingyas) came here to burn our houses and we followed them and burned theirs," said Thin Yin Nu, a Buddhist Rakhine in Byaing Phyu, a village close to a Rohingya settlement.
"Both sides have seen dead and things cannot be okay again." (Reporting by a Reuters staff reporter; Editing by Martin Petty)