YANGON (Reuters) - Unrest in Myanmar’s northwest is taking a “terrible toll” on children, the U.N. children’s agency UNICEF said and called for full humanitarian access to the Muslim-majority north of Rakhine state.

Tens of thousands of people have been cut off from food and other aid normally provided by international agencies since deadly attacks on police guard posts along the border with Bangladesh on Oct. 9.

“While some aid has been delivered in recent days, UNICEF calls for full resumption of essential services and the urgent lifting of all restrictions of movement of health and other professionals so they can safely reach children and families,” UNICEF said in a statement from New York on Tuesday.

Troops have poured into the region in response to the attacks, in which assailants believed to be from the mostly stateless Rohingya group killed nine policemen.

The army declared the area an “operation zone”, blocked aid and barred foreign journalists and observers from the Maungdaw area. Residents and human rights monitors say extra-judicial killings, rape and arbitrary arrests have taken place.

Security forces have killed 33 alleged attackers, while five soldiers and one policeman have been killed, according to state-run media.

On Tuesday, the World Food Programme said it had begun the first deliveries of food aid in Maungdaw in more than a month, reaching about 6,500 people in four villages affected by the violence.

WFP said its assistance would normally reach 152,000 people in northern Rakhine.

The majority in the area are Rohingya Muslims, a 1.1 million strong group in Rakhine who face restrictions on their movements and access to services.

The malnutrition rate is 19 percent among children under five in Maungdaw, according to U.N. statistics.

The limited access came after a request from diplomats and the U.N.’s top official in Myanmar, who visited Maungdaw over two days last week. The delegation called for an independent investigation into alleged rights abuses and for aid programs to be allowed to resume.

U.N. officials and diplomats from Western countries privately expressed concern at the public response to the crisis from the government of Nobel laureate Aung San Suu Kyi, which has flatly denied allegations of abuses committed by the military.

State-run newspapers have said last week’s visit by diplomats - who stressed they were not able to verify claims of rights abuses - revealed that the allegations were baseless. A key official spokesman singled out a journalist reporting allegations and said the claims were concocted by people with links to insurgents.