The U.N. committees for women's and children's rights called on Myanmar's authorities yesterday to immediately stop violence in northern Rakhine state, which hundreds of thousands of Rohingya Muslims have fled in the past six weeks.

"We are particularly worried about the fate of Rohingya women and children subject to serious violations of their human rights, including killings, rape and forced displacement," the committees on the elimination of discrimination against women and on the rights of the child said in a statement.

"Such violations may amount to crimes against humanity and we are deeply concerned at the state's failure to put an end to these shocking human rights violations being committed at the behest of the military and other security forces."

Meanwhile, humanitarian organizations helping Rohingya Muslim refugees in Bangladesh said yesterday they need $434 million over the next six months to help up to 1.2 million people, most of them children, in dire need of life-saving assistance.

There are an estimated 809,000 Rohingya sheltering in Bangladesh after fleeing violence and persecution in Myanmar, more than half a million of whom have arrived since Aug. 25 to join 300,000 Rohingya who are already there.

"The Rohingya population in Cox's Bazar is highly vulnerable, many having experienced severe trauma, and are now living in extremely difficult conditions," Robert Watkins, U.N. resident coordinator in Bangladesh, said in a statement, referring to the area where most Rohingya are living.

Bangladesh and humanitarian organizations are struggling to help the 509,000 Rohingya who have arrived since attacks by Rohingya militants in August triggered a Myanmar military offensive that the United Nations has branded ethnic cleansing.

Turkey has been at the forefront of providing aid to Rohingya refugees, and President Recep Tayyip Erdogan has raised the issue at the U.N. The Rohingya, described by the U.N. as the world's most persecuted people, have faced heightened fears of attack since dozens were killed in communal violence in 2012.

Myanmar leader Aung San Suu Kyi has faced scathing criticism for not doing more to stop the violence. A British honor granted to Myanmar's leader has been withdrawn amid atrocities targeting the Muslim minority in her country, causing more than half a million Rohingya to take refuge in neighboring Bangladesh. Oxford City Council leader Bob Price supported the motion to strip State Counselor Aung San Suu Kyi of the honor. People are "absolutely appalled" by the situation in Myanmar, Price said. He called it "extraordinary" that Suu Kyi had not spoken out about the atrocities in Myanmar.