The United Nations Special Rapporteur on human rights in Myanmar, Tomás Ojea Quintana, has expressed serious concerns over the spread of violence between Muslim and Buddhist communities in Myanmar.

He says Myanmar security officials often stand by or are complicit in atrocities committed in attacks on minority groups.

His call came on the day police in Myanmar said they were investigating mosque officials for possible negligence after a pre-dawn fire swept through an Islamic religious dormitory, killing 14 orphaned children.

Police deployed riot police, but called for calm after authorities attributed the blaze to an electrical short circuit.

In a statement Tuesday he urged bold steps by the Myanmar government to counteract this frightening trend.

"The Government must take immediate action to stop the violence from spreading to other parts of the country and undermining the reform process.

"This includes stemming campaigns of discrimination and hate speech which are fuelling racist and, in particular, anti-Muslim feeling in the country.

"And it involves holding to account those responsible for acts of violence and destruction against religious and ethnic minorities," Ojea Quintana said.

Myanmar has made much progress in human rights since the release of Nobel Peace Prize laureate Aung San Suu Kyi in 2010, but rights organizations say religious minorities remain persecuted.

At the end of March a delegation from the Chin Human Rights Organization met this week with members of the U.S. Congress, the State Department and the U.S. Commission on International Religious Freedom.

Christian Solidarity Worldwide and the Chin Human Rights Organization on Saturday called on the international community to put ethnic and religious minority rights higher up the reforms agenda for Myanmar after a week of lobbying in both Brussels and Washington DC.

In Washington the Chin organization discussed its latest report documenting the persecution of ethnic Chin in Myanmar, which is also known as Burma.

The Special Rapporteur's statement did not mention the allegations involving the Chin.

Rakhine State

Ojea Quintana noted, "The warning signs have been there since the communal violence in Rakhine State last June and the Government has simply not done enough to address the spread of discrimination and prejudice against Muslim communities across the country, and to tackle the organized and coordinated mobs that are inciting hatred and violently attacking Muslim communities."

The U.N. statement said last week saw violence between Muslim and Buddhist communities in Mandalay region in central Myanmar that left 12,000 persons displaced and unconfirmed numbers dead.

Subsequently, a curfew and state of emergency has been imposed in four townships in Mandalay region.

There are reports of violence spreading to Bago and Yangon.

In June and October last year, inter-communal violence in Rakhine State, Northwest Myanmar, left 120,000 internally displaced and, according to Government figures, nearly 200 dead.

Ojea Quintana welcomed calls from government leaders, including a televised address by the Burmese president, Thein Sein, to the nation earlier Tuesday, calling for compassion, tolerance, understanding and empathy amongst people of all faiths in Myanmar.

He also noted the president's warning to "political opportunists" and "religious extremists" not to misuse religion to incite hatred.

However, the Special Rapporteur said he believes Myanmar State authorities need to do much more.

This includes addressing allegations that some State officials, including local politicians and administrators, have been encouraging discriminatory views and inciting hatred.

Social media

The Rapporteur also expressed concern about religious leaders or their supporters publicly spreading hate speech, including through social media.

"I have seen worrying footage of religious leaders, including Buddhist monks, seemingly advocating religious intolerance. The government must clearly distance itself from such incitement to hatred, and instruct its officials to do likewise.

"Although Myanmar is a majority Buddhist country, the government must promote tolerance of all faiths and religions."

Of Myanmar's population of some 56 million people, Buddhists make up about 89 percent, while Christians and Muslims each account for about four percent.

"I have received reports of State involvement in some of the acts of violence, and of instances where the military, police and other civilian law enforcement forces have been standing by while atrocities have been committed before their very eyes, including by well-organized ultra-nationalist Buddhist mobs," said the UN specialist.

"This may indicate direct involvement by some sections of the State or implicit collusion and support for such actions."

He said other allegations he received indicated that the military and police may be arbitrarily detaining people based on religious and ethnic profiling.