Myanmar's border guards buried nine officers killed in the western state of Rakhine following three deadly attacks on posts along the northwestern frontier with Bangladesh.

Most people in the area are Muslim Rohingya, a stateless minority whom Buddhist nationalists vilify as illegal immigrants from Bangladesh - even though many have lived in Myanmar for generations. 

Officers carried wooden coffins draped with national flags through rain and thick mud on Tuesday before laying them to rest in a cemetery in the town of Maungdaw.

Troops have poured into the town and surrounding area after Sunday's attacks by what authorities have described as mobs armed with knives and homemade weapons.

At least four people were killed in clashes with soldiers who hunted for the attackers, police said. Locals put the toll at seven and said they were unarmed residents.

Myanmar's de facto leader Aung San Suu Kyi has appealed for calm [Khine Htoo Mrat/AFP]

On Tuesday, residents reported sporadic gunfire in some villages north of Maungdaw. 

One local teacher, who did not give her name, said she had been hiding in a house along with about 20 other school staff and students, too scared to come out because of the sound of gunfire. 

"We haven't eaten for two days. The situation is not so good," she told AFP news agency from Ngakhura, 42km from Maungdaw. "We heard fighting here and there. We do not dare to go out."

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Two Muslim men captured during Sunday's attacks have reportedly confessed, Rakhine state police Major Sein Lwin told the Reuters news agency.

Pictures sent to AFP by a photographer in the area showed one of them, bedraggled and topless, being interrogated by intelligence officers in Sittwe.

He said the men, who were charged with murder, conspiracy to murder, and the assault of civil servants, said the attacks had been planned by a single "leader".

Lwin declined to name the leader, but said he had ties to an unnamed armed group operating across the Bangladesh border, which Myanmar has closed, and where Bangladesh has stepped up patrols.

Two Muslim men captured during Sunday's attacks have reportedly confessed [Stringer/AFP]

Some officials have pointed the finger at the Rohingya, including a long-silent armed group called the Rohingya Solidarity Organisation, while others have blamed Bangladeshis and drug-traffickers.

Some activists said the military may be using the border attacks as a pretext to target the long-persecuted Rohingya.

"There's historical precedent for the authorities using lethal force against Rohingya in the area and we're concerned a crackdown is unfolding," said Matthew Smith, chief executive of Fortify Rights.

Vijay Nambiar, the UN special adviser on Myanmar, called on civilians in troubled Rakhine state on Tuesday to exercise maximum restraint and refrain from responding to the recent fighting.

"At this delicate juncture," Nambiar said, "the local communities at all levels must refuse to be provoked by these incidents and their leaders must work actively to prevent incitement of animosity or mutual hatred between Buddhist and Muslim communities."

Authorities have extended a regional curfew to between 7pm and 6am [Minn Theim Khaine/EPA]

Nambiar said authorities in the capital Naypyidaw had informed him "that firm instructions have been issued from the highest levels" for officials to take action within the law "to maintain peace and avoid escalation".

Authorities have extended a regional curfew to between 7pm and 6am, and closing about 400 schools around the area for the next two weeks.

Myanmar's de facto leader Aung San Suu Kyi has appealed for calm and several ministers and army top brass flew to Rakhine's capital Sittwe on Tuesday to try to ease tensions in nearby displacement camps.

In August, Suu Kyi appointed former UN chief Kofi Annan to chair an advisory panel on Rakhine state that visited the area for the first time in September, but it has yet to go to the northern Muslim-majority townships.

The violence in 2012 killed more than 100 people and left about 125,000, mostly Rohingya, unable to return home. 

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Source: News Agencies