A fatal Red Cross truck accident that killed nine in Bangladesh Thursday and attacks by a Buddhist mob in Myanmar on an aid shipment Wednesday have severely hampered aid delivery to the Rohingya Muslim refugees displaced by violence.

Communal tensions remain high across Rakhine state after last month's massive army crackdown that drove more than 420,000 people into Bangladesh in what the U.N. calls a campaign of "ethnic cleansing."

Aid groups fear that tens of thousands trapped there were desperate for support, even though humanitarian access was still hampered despite the government's promise to allow safe passage.

The crisis has prompted a global chorus of condemnation against the country's de-facto leader Aung San Suu Kyi for refusing to blame Myanmar's powerful military for the crackdown.

A 300-strong Buddhist mob in Rakhine's state capital Sittwe massed late Wednesday at a jetty where a boat carrying relief goods was preparing to travel upriver to hard-hit Maungdaw.

They forced the ICRC (International Committee of the Red Cross) to unload the aid from the boat and prevented the vessel from leaving, state-backed Global New Light of Myanmar newspaper reported Thursday, quoting Myanmar's Information Committee.

Police officers arrived as the crowd neared the jetty, while Buddhist monks also tried to calm the mob, but people began to hurl "stones and Molotov (cocktails) at the riot police," the report said.

Eight people were detained and several police officers were injured before order was restored.

The ICRC confirmed the incident and said they would continue to try and deliver relief to the area.

"We will carry on, nothing has been put on hold," Graziella Leite Piccoli, ICRC spokeswoman for Asia, told AFP.

News of clashes in the violence-wracked state, where security forces have been accused of razing scores of Rohingya villages, emerged as a truck hired by the ICRC crashed in Bangladesh, killing nine people and injuring 10 others.

"It was carrying food to Rohingya refugees on the border, including those stranded in the no man's land," Yasir Arafat, deputy police chief of Bandarban district, told AFP.

Hundreds of thousands of Rohingya refugees have streamed into Bangladesh since the end of August, cramming into ill-equipped camps and makeshift shelters near the border town of Cox's Bazar.

Aid groups have been overwhelmed by the scope of the influx and warned of an unfolding humanitarian crisis in the camps, where they are scrambling to build housing and provide food rations.

The Bangladesh government is building a massive new camp nearby to shelter 400,000 people, but the U.N. says it will take time before it is equipped with tents, toilets and medical facilities.

Myanmar's government has come under fire by global leaders urging the country to address the crisis and condemn the military for attacks on the Rohingya, who are widely reviled as "Bengali" immigrants in Buddhist-majority Myanmar.

But Myanmar, which has been accused of downplaying the violence, insisted the crisis was easing.

"I am happy to inform you that the situation has improved," Myanmar's second vice president Henry Van Thio told the U.N. General Assembly Wednesday.

He said there have been no clashes since Sept. 5 and added that his government was committed to allowing aid in.

"Humanitarian assistance is our first priority. We are committed to ensuring that aid is received by all those in need, without discrimination," he said.

There were more than a million Rohingyas in Myanmar before the current crisis, though nearly half have fled since the deadly attacks on military posts by The Arakan Rohingya Salvation Army (ARSA) militants on Aug. 25.

They have long been ostracized in Myanmar, where they are considered illegal immigrants and face severe restrictions.