Hundreds of protesters tried to stop Red Cross workers loading a boat with about 50 tonnes of relief supplies in the Rakhine capital, Sittwe, the authorities said.
More than 420,000 Rohingya Muslims have now crossed the border to Bangladesh, fleeing a military crackdown that followed reported attacks by Rohingya militants on August 25.
A UN spokesman said the incident would disrupt already extremely patchy aid delivery to the border with Bangladesh.
“People thought the aid was only for the Bengalis,” secretary of the Rakhine government Tin Maung Swe told Reuters, using the common Burmese term that implies the Muslim community is made up of illegal immigrants from Bangladesh.
Protesters with sticks and metal bars threw petrol bombs and about 200 police dispersed them by firing in the air, an unnamed witness said.
None of the aid workers were hurt, said Maria Cecilia Goin of the International Committee of the Red Cross.
Myanmar’s Vice-President Henry Van Thio told the UN General Assembly that the government was “deeply concerned” about the Rakhine exodus, saying the authorities were investigating “a problem of significant magnitude”.
The second vice-president claimed the reason for the refugee crisis was unclear and that the “great majority” of Muslims had stayed behind.
He said not just Muslims but other ethnic groups had left the conflict area, and the military had been told to “take full measures to avoid collateral damage and the harming of innocent civilians”. State Counsellor Aung San Suu Kyi made very similar comments this week.
She had been expected to address the New York gathering but pulled out amid the growing Rakhine crisis.
Donald Trump has reportedly told the UN Security Council to take “strong and swift action” to end the Rakhine violence.
US Deputy Assistant Secretary of State Patrick Murphy is in the country and is due to meet government and community representatives in Sittwe.
The most powerful figure in Myanmar, Senior General Min Aung Hlaing, this week visited a Rakhine army camp that was attacked on August 25.
“This was a British colony over 100 years ago, we are facing the consequences of their reckless acts until now,” he said, according to the military or Tatmadaw.
The former imperial master, Britain, has axed a military training programme this week in response to the violence.
The Tatmadaw said five officers in Britain were returning home and “no trainees … will be sent to Britain any more”.
The Rohingya have suffered increasing persecution since 2012. Picture credit: Flickr