At least 25 people have died while hundreds more have fled.

Burma’s President Thein Sein has warned the unrest could spread to other states and has formed a committee to investigate.

The Project Director for South East Asia for the International Crisis Group, Jim Della Giacoma has told Radio Australia’s Connect Asia program hundreds of houses have been burned in the violence and there is a potential there have been more casualties than the official figures.

"While there is a much higher level of transparency than we might have expected 18 months ago in Burma, it is still an area where there is not free access for the media or for NGOs like ourselves to do the kind of research that would be able to verify the exact numbers," he said.

Burmese govt urged to protect civilians amid sectarian violence
Southeast Asian human rights groups have urged the Burmese government and the international community to protect all civilians from religious and ethnic violence in western Burma.

In a joint statement, Forum-Asia, Altsean-Burma, Indonesia’s Kontras and the LBH legal aid institute have voiced deep alarm at the continued sectarian violence in Burma’s Arakan state.

Debbie Stodhart, from ALTSEAN Burma, told Radio Australia’s Asia Pacific program the UN must act to protect all civilians caught up in the unrest.

"Mr Nambiar needs to be focussing on the fact that there has to be decisive action to protect the vulnerable communities from both sides, but in particular the Muslim community which has been targeted with language that seems to endorse violence upon Muslims because they are Muslims," she said.

She says the situation has been going on for too long.

"We’ve been in a situation for many decades now, where the Rohingya have suffered genocide-like conditions, restrictions on marriage, restrictions on practising their religion or even on moving around within the state," she said.

"The UN has already acknowledged that they’re one of the most threatened communities in the world."

Ms Stodhart says the government needs to do more to stop the tensions and protect ethnic minority groups.

"The government has not engaged in any legal reform that will grant minorities protection from this type of violence," she said.

"They’ve not sought to remove any discriminatory policies and practices.

"This is not just a problem affecting Arakan state.

"This is a problem affecting most ethnic groups, including in Kachin state, where the war in Kachin state has been going on for a year already."

Burma’s Muslims of Indian, Chinese and Bangladeshi descent, account for an estimated 4 per cent of the roughly 60 million population in a country where, for many people, Buddhism forms an intrinsic part of national identity.

According to the UN, there are nearly 800,000 Rohingya living in Burma, mostly in Arakan.

Another 1 million or more are thought to live in other countries