The United States on Saturday called for an end to a mobile internet shutdown in two strife-torn states in Myanmar, saying the cut-off undermines transparency amid clashes between the military and Arakan Army (AA).

Myanmar's government last week took the unprecedented step of ordering mobile phone operators to shut down all internet data across at least eight townships in Rakhine state and one in neighbouring Chin state.

The move came as the military moved against the AA which is fighting for more autonomy for the region's ethnic Rakhine Buddhists.

"Internet service should be restored without delay," the US State Department said in a statement.

"Resumption of service would help facilitate transparency in and accountability for what the government claims are law enforcement actions aimed at preventing further outbreaks of violence in the affected areas," it added.

Human Rights Watch (HRW) on Friday said humanitarian groups had reported the shutdown "is creating difficulties for them to carry out their work."

"WhatsApp is key for international nonprofits operating in Rakhine, and working without it creates additional difficulties," it said.

The United Nations has warned that the internet shutdown amid Myanmar military "clearance operations" against the AA could be "cover for committing gross human rights violations against the civilian population."

Myanmar has deployed thousands of troops to the western region, which has seen more than 35,000 people fleeing their homes to escape heavy artillery fire in the violence that has spilt over into Chin state.

Both sides stand accused of committing abuses and dozens of civilians have been killed in crossfire and shellings, even while taking refuge in monasteries.

© AFP