YANGON (Reuters) - Senior diplomats from the United States, China, Britain and the European Union will this week visit Myanmar's troubled northern Rakhine State, which has been cut off to aid workers and observers for more than three weeks, sources said.

The diplomats, and the top United Nations representative in Myanmar, will set off for Maungdaw on Wednesday, six people with direct knowledge of the matter told Reuters on Tuesday.

Troops have poured into the area since militants believed to be Rohingya Muslims launched coordinated attacks on border posts on Oct. 9, killing nine police officers. The government says five soldiers and at least 33 alleged attackers have been killed in the area.

Residents and human rights advocates have said government forces have committed abuses including summary executions, rape and setting fire to homes.

The government of Nobel laureate Aung San Suu Kyi has denied any abuses have been committed.

The sources, who spoke about the planned trip on condition of anonymity due to the sensitivity of the matter, said the invitation by the government was in response to requests for access to the Rohingya-majority area, which has been designated a military "operation zone".

Over two days, the officials will visit Maungdaw by helicopter from the state capital Sittwe, the people said, although the government had not shared a detailed itinerary.

However, officials expressed scepticism that the high-level diplomatic mission will address the concerns raised by the international community.

United Nations experts have publicly called for the government to investigate allegations of human rights abuses.

Diplomats have also pressured the Myanmar government to allow humanitarian aid, including World Food Programme assistance and mobile clinics, to be restored.

(Reporting by Yangon newsroom; Editing by Ian Geoghegan)