A Buddhist mob in Myanmar threw petrol bombs in a bid to block a boat carrying aid for Rohingya Muslims in conflict-hit Rakhine state before police fired warning shots to disperse them, a media report said.

The incident happened on Wednesday when the boat was being loaded with relief supplies from the International Committee of the Red Cross (ICRC) in Rakhine’s capital Sittwe, BBC reported.

The aid shipment was bound for Rakhine, where a military campaign sparked by militant attacks had forced hundreds of thousands of Rohingya Muslims to flee the country.

The mob, some carrying sticks and metal bars, threw petrol bombs. Policemen were forced to disperse them by shooting into the air. Several arrests were made, officials said.

ICRC spokeswoman Graziella Leite Piccoli confirmed the incident.

She said aid workers “managed to engage the people in dialogue, communicating that we work transparently and were there for everyone in need”, and were eventually left alone with the supplies.

The boat remains in Sittwe. A spokesman for the UN said the incident would further disrupt already extremely patchy aid delivery.

The Rohingya refugees began fleeing Myanmar from August 25 when Arakan Rohingya Salvation Army (ARSA) rebels attacked police checkposts and killed 12 security personnel, triggering a military crackdown.

At least 420,000 Rohingya have since fled to Bangladesh to escape what a senior UN official called a “textbook example of ethnic cleansing”.