SITTWE, Myanmar (Reuters) – Hundreds of Buddhists in Myanmar tried to block a shipment of aid to Muslims in Rakhine state where the United Nations has accused the military of ethnic cleansing, with a witness saying protesters threw petrol bombs before police dispersed them by firing into the air.

The protest was testament to rising communal animosity that threatens to complicate the delivery of vital supplies, and came as U.S. President Donald Trump called for a quick end to the violence that has raised concern about Myanmar’s transition from military rule.

The aid shipment, being organized by the International Committee of the Red Cross (ICRC), was bound for the north of the state where insurgent attacks on Aug. 25 sparked a military backlash.

The violence has sent more than 420,000 Rohingya Muslims fleeing to neighboring Bangladesh but many remain in Myanmar, hiding in fear of being caught up in more violence without food and other supplies, aid workers believe.

Several hundred people tried to stop a boat being loaded with about 50 tonnes of aid at a dock in the Rakhine State capital of Sittwe late on Wednesday, a government information office said on Thursday.

Protesters, some carrying sticks and metal bars, threw petrol bombs and about 200 police were forced to disperse them by shooting into the air, a witness said, adding that he saw some injured people. Eight people were detained, the government information office said in a release.

A spokeswoman for the ICRC was not immediately available for comment. Police in Sittwe were also not immediately available for comment.

Tension between majority Buddhists and Rohingya in Rakhine state has simmered for decades but it has exploded in violence several times over the past few years, as old prejudices have surfaced with the end of decades of military rule.

The latest bout of bloodshed began in August when Rohingya insurgents attacked about 30 police posts and an army camp, killing about 12 people.

The government says more than 400 people, most of them insurgents have been killed since then.

Rights monitors and fleeing Rohingya say the army and Rakhine Buddhist vigilantes have mounted a campaign aimed at driving out the Muslim population and torching their villages.

Myanmar rejects the charge, saying its forces are tackling insurgents of the Arakan Rohingya Salvation Army who it has accused of setting the fires and attacking civilians.

TRUMP CALLS FOR SWIFT ACTION

The violence and the exodus of refugees has brought International condemnation and raised questions about the commitment of government leader Aung San Suu Kyi to human rights, and prospects for Myanmar’s political and economic development.

Suu Kyi addressed the nation about the crisis on Tuesday and condemned abuses and said all violators would be punished, adding that she was committed to peace and the rule of law.

However, she did not address U.N. accusations of ethnic cleansing by the military, which is in charge of security.

U.S. President Donald Trump wanted the U.N. Security Council to take “strong and swift action” to end the violence, U.S. Vice President Mike Pence said on Wednesday, declaring the crisis a threat to the region and world.

Pence repeated a U.S. call for the military to end the violence and support diplomatic efforts for a long-term solution for the Rohingya, who are denied citizenship in a country where many Buddhists regard them as illegal immigrants.

It was the strongest U.S. government response yet to the violence.

U.S. Deputy Assistant Secretary of State Patrick Murphy is in Myanmar and was due to meet government officials and representatives of different communities in Sittwe, the capital of Rakhine state.

Military chief Senior General Min Aung Hlaing on Wednesday visited an army camp in the state that was attacked on Aug. 25.

“This was a British colony over 100 years ago, we are facing the consequences of their reckless acts until now,” he was quoted as saying in a military release.

This week, Britain suspended a training program for Myanmar officers because of the violence and called on the army to stop the violence.

The Myanmar military said five officers in Britain were being brought home and “no trainees .. will be sent to Britain any more”.