The United Nations humanitarian chief described the plight of Burma's Rohingya Muslims as “dire,” as she toured crowded refugee camps filled with those who have fled deadly communal violence.

Humanitarian chief Valerie Amos says she witnessed thousands of people in “overcrowded, substandard shelter with poor sanitation” during her tour on Thursday of several camps in western Rakhine state.

The U.N. says over 115,000 people have been displaced across Rakhine after violence between Muslims and Buddhists broke out in June and again in October, killing dozens and destroying thousands of homes.

Though the deadly violence has calmed, Amos says tensions between the communities remain “very high” and that many are “living in fear.” She said she was shocked that Burmese soldiers are keeping communities away from each other in an attempt to enforce calm.

Rights groups have criticized Burma for depriving many Rohingya of many basic rights, including citizenship. Amos said Thursday that many displaced Rohingya do not have jobs, children are not in school, and cannot leave the refugee camps because of restrictions on their movement.

Although Amos said that coordination between Burma's government and U.N. agencies “has improved significantly,” she called on the country's political leaders to support the U.N. relief efforts. She said leaders should explain to local communities why they are providing relief, saying security threats to aid workers are a “major challenge.”

The U.N. is still looking for over 60 percent of the $68 million it says is necessary to respond to the humanitarian situation in Burma.