YANGON--Rebels in Myanmar's Rakhine region said a captured official from Aung San Suu Kyi's ruling party has died, two weeks after being taken for organizing protests against genocide accusations faced by Myanmar at the World Court.

The Arakan Army rebels said Buthidaung National League for Democracy (NLD) Chairman Ye Thein, the most senior civilian official to die in the growing insurgency, was killed on Monday in an attack on the rebels by Myanmar's army. There was no independent confirmation.

The incident underscored the increasing loss of government control in a region which came to world attention when 700,000 Rohingya Muslims fled to Bangladesh to escape an army crackdown on a different rebel group in 2017.

The Arakan Army said its positions had come under attack from Myanmar's army.

"Due to big explosions, some detainees died and some were wounded. The NLD chairman from Buthidaung, Ye Thein, died on scene," the Arakan Army said in the statement. It said he had been taken prisoner on Dec. 11.

Tens of thousands of people have been displaced in Rakhine since clashes between the Arakan Army and the army began around a year ago.

The insurgents, whose forces are from the largely Buddhist Rakhine people, are fighting for greater autonomy.

They say they have no links to the Rohingya rebel group whose attacks sparked the 2017 army crackdown that led to the accusations of genocide brought against Myanmar at the International Court of Justice by The Gambia.

The Arakan Army is among several ethnic armed factions that have said they support the case against Myanmar.

Suu Kyi, Myanmar's de facto ruler, personally led Myanmar's defense against the accusations at hearings in The Hague earlier this month.

The army made no comment on the report of the NLD official's death. NLD party spokesman Myo Nyunt said it was the responsibility of the Arakan Army.