KAMPALA, Uganda - Scores of people have been killed in fighting between Ugandan forces and a tribal militia in a remote district near the border with Congo, Ugandan officials said Sunday as security forces battled armed men protecting a tribal king who is accused of leading the rebels.

At least 54 people, including 41 rebels and 13 police officers, have been killed in clashes in Uganda’s Rwenzori region, police spokesman Felix Kaweesi told reporters. Four police officials and four soldiers have been wounded, he said.

The killings are an escalation of a long-running conflict between Ugandan security forces and rebels who are believed to be loyal to a tribal king, Charles Wesley Mumbere, a critic of the country’s long-time president. Mumbere was arrested after the killings, accused of inciting violence, reports the BBC.

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Mumbere worked as a nurse’s aide in Maryland and Pennsylvania for years, caring for the elderly and sick, before being crowned king in 2009. President Yoweri Museveni has officially recognized Mumbere’s 300,000-strong Rwenzururu Kingdom. Government recognition does not grant any executive power but allows the monarchs to determine cultural and social issues affecting their people.

The King of Uganda’s Mountains of the Moon has undergone many transformations in his life - from teenage leader of a rebel force to impoverished student to a nursing home assistant working two jobs in the U.S., where he lived for nearly 25 years.

He inherited the title when his father, Isaya Mukirania Kibanzanga, died while leading a secessionist group in the Rwenzori Mountains, otherwise known as the Mountains of the Moon. The rebels were protesting the oppression of their Bakonzo ethnic group by their then-rulers, the Toro Kingdom.

The Bakonzo demanded to be recognized as a separate entity and named Kibanzanga, a former primary school teacher, as their king in 1963.

Shortly after Kibanzanga died, his son led the fighters down from the mountains to hand in their weapons. Mumbere went to the United States in 1984 on a Uganda government scholarship, attending a business school until Uganda’s leadership changed and the stipend was stopped.

Now it appears the peace between the Mountains of the Moon and the Ugandan government has ended.

Gunfire rang out outside the king’s palace Sunday as Ugandan troops tried to break into the premises and disarm his guards.

After the rebels had killed four police officers, security forces launched an operation to disarm the royal guards and other armed supporters of Mumbere in the region, government spokesman Col. Shaban Bantariza told The Associated Press.

Mumbere and some of his supporters are now calling for secession from Uganda, according to Bantariza, who said he had seen copies of money printed by the secessionist group, which is hoping to create a republic known as Yiira.

Mumbere has denied any role in the attacks on police posts.

The western district of Kasese, where Mumbere is based, is a hotbed of opposition to President Yoweri Museveni, who lost there in the last presidential polls.

Some of the rebels had climbed high up the Rwenzori mountains and set up military camps from which they were said to run a small government, even collecting taxes from the people they control. The rebels are armed with modern weapons and improvised explosive devices, according to Bantariza.

“They had shut down life in the areas they occupied,” he said. “We shall beat those who want to cause trouble on our land.”

Museveni, in power since 1986, has struggled to win over the support of the Bakonzo people in presidential elections. There are frequent land disputes in the area, with many accusing the government of sponsoring land grabs. A new plan to divide up Kasese into two parts has also been fiercely opposed.

In the 1990s, the area was the scene of a violent insurgency by the Allied Democratic Forces, a rebel group that now is based in Congo after being forced out of Uganda.