By Paul Carsten
BANGKOK, April 22 (Reuters) - Authorities in Myanmar's Rakhine State aided the ethnic cleansing of Rohingya Muslims last year in crimes against humanity that have sparked anti-Muslim violence elsewhere in the country, Human Rights Watch (HRW) said on Monday.
Security forces were complicit in disarming Rohingya Muslims of makeshift weapons and standing by, or even joining in, as Rakhine Buddhist mobs killed men, women and children in June and October 2012, New York-based HRW said.
"While the state security forces in some instances intervened to prevent violence and protect fleeing Muslims, more frequently they stood aside during attacks or directly supported the assailants, committing killings and other abuses," the report said of the unrest, in which at least 110 people died.
The failure to investigate properly or punish state officials had emboldened those behind campaigns against Muslims elsewhere, said Phil Robertson, deputy Asia director at HRW, referring to violence in central Myanmar that killed more than 43 people in March and displaced at least 12,000.
"People are allowed to incite and instigate in a coordinated campaign - this is the lesson taken in by others," Robertson told Reuters. "What happened in Arakan (Rakhine) has helped spark radical anti-Muslim activity."
Myanmar government officials could not be reached for comment on the report.
Human rights abuses still take place in fast-changing Myanmar despite widespread political, social and economic reforms by a quasi-civilian government that took power in March 2011 and convinced the West to suspend most sanctions to allow aid and investment into one of Asia's poorest countries.
A decision expected on Monday by the European Union to lift all but its arms embargoes would only weaken the hand of Western powers seeking to clean up Myanmar's poor human rights record, Robertson said.
"They're going to be hostage to what the military and government does," he said. "They're not going to have the kind of leverage and capacity to push back on the government if it becomes more oppressive."
The report into the Rakhine state violence, which called for international pressure on the government, said authorities had blocked aid from going into the squalid camps occupied by stateless Rohingya and Kaman Muslims, exposing them to malnourishment and diseases such as cholera or typhoid.
Robertson described the segregation of Muslims as "ghettoisation" that left them vulnerable to abuse.
More than 120,000 people fled arson and machete attacks in Rakhine state and thousands have embarked on perilous journeys on rickety wooden boats to other countries, where they are prey to human trafficking gangs.
An estimated 800,000 stateless Rohingyas live in Myanmar, where the authorities restrict their movements and access to employment and consider them illegal immigrants from Bangladesh.
The HRW report said more than 70 Rohingyas were killed in Mrauk-U Township's Yan Thei village in October, among them 28 children and infants who were hacked to death. (Editing by Martin Petty and Paul Tait)