Doctors Without Borders said Friday it has been expelled from Burma and that tens of thousands of lives are at risk. The decision came after the humanitarian group reported it treated nearly two dozen Rohingya Muslim victims of communal violence in Rakhine state, which the government has denied.

The humanitarian group said it was "deeply shocked" by Burma’s decision to expel it after two decades of work in the country.

The United States said it was very concerned and urged the government to continue to provide "unfettered" access for humanitarian agencies.

"Today for the first time in MSF's history of operations in the country, HIV/AIDS clinics in Rakhine, Shan and Kachin states, as well as Rangoon division, were closed and patients were unable to receive the treatment they needed," the Doctors Without Borders said in a statement, using the French acronym for its name.

As Burma’s main provider of HIV drugs, supplying treatment to 30,000 people, the group described the impact as devastating.

Attack in Rakhine

Burma’s presidential spokesman Ye Htut had criticized Doctors Without Borders in the Myanmar Freedom newspaper for hiring "Bengalis," the term the government uses for the Rohingya Muslim minority, and lacked transparency in its work.

Myanmar Asia Cyclone

Burma's presidential spokesperson Ye Htut accused Doctors Without Borders of misleading the world about an attack last month in remote northern Rakhine. (Khin Maung Win/Associated Press)

He also accused the group of misleading the world about an attack last month in the remote northern part of Rakhine. The United Nations says more than 40 Rohingya may have been killed, but the government has vehemently denied allegations that a Buddhist mob rampaged through a village, killing women and children. It says one policeman was killed by Rohingya and no other violence occurred.

Doctors Without Borders said it treated 22 injured and traumatized Rohingya.

Repeated attempts to reach Ye Htut for comment were unsuccessful Friday.

Burma, also known as Myanmar, is a predominantly Buddhist nation of 60 million that only recently emerged from a half-century of military rule. Since then, ethnic tensions have swept Rakhine state, raising concerns from the United States and others that the bloodshed could undermine democratic reforms. Up to 280 people have been killed and tens of thousands more have fled their homes, most of them Rohingya.

Humanitarian aid

Since the violence erupted in June 2012, Doctors Without Borders has worked in 15 camps for the displaced people in Rakhine state. For many of the sickest patients, the organization offers the best and sometimes only care, because traveling outside the camps for treatment in local Buddhist-run hospitals can be dangerous and expensive. The aid group has worked to help smooth the referral process for emergency transport from some camps.

Myanmar Broken Health

Laboratory workers sort tuberculosis test samples at a clinic for transmittable diseases funded by Doctors Without Borders on the outskirts of Rangoon, Burma, in this photo from Aug. 28, 2012. (Alexander F. Yuan/Associated Press)

Due to increasing threats and intimidation from a group of Rakhine Buddhists who have been holding near daily protests against Doctors Without Borders, the organization has said its activities have been severely hampered and that it has not received enough government support.

"We urge the government to continue to work with the international community to provide humanitarian assistance to communities in need and to ensure unfettered access for humanitarian agencies," U.S. State Department spokeswoman Jen Psaki told reporters in Washington.

Democratic Rep. Joe Crowley, one of the most prominent voices in the U.S. Congress on Burma, also reacted to the reported expulsion. "It is the responsibility of the Burmese government to protect civilians. This is deeply troubling," he said in a tweet.

Psaki said the U.S. understands that Burma’s government and Doctors Without Borders are in discussions on the group resuming operations.