SYDNEY (Reuters) - Armed rioters angered over the failure of a court challenge to the election of a regional governor have burned an airplane on the tarmac in Papua New Guinea’s rugged highlands, and torched houses and government buildings, police and a witness said.

Violence has long ravaged the poor but resource-rich and remote interior of the Pacific Ocean nation, where tribal and land disputes overlay local politics.

The latest outburst, which has prompted the prime minister to send security reinforcements, comes amid a spike in lawlessness since February’s huge earthquake killed at least 100 people, destroying roads and crops and taking out services.

“It’s a big, big disruption,” policeman Naring Bongi told Reuters by telephone from Mendi, the capital of the Southern Highlands province, about 500 km (310 miles) northwest of the national capital Port Moresby.

Between 100 and 200 furious men armed with sticks and guns arrived from surrounding villages in flatbed trucks when they heard of the failure of the court challenge to last September’s election of a political opponent as governor, Bongi said.

They set fire to the plane before moving into the township, setting ablaze houses and two court buildings, he said. Nobody was hurt or killed and the men left by nightfall.

“They had firearms,” he said. “We were confronting them but we didn’t stop it because these men are really mad. If we shot them they would kill us. Whether they will carry this on again tomorrow, or onwards, I don’t know.”

Reuters was unable to confirm the court’s verdict after business hours on Thursday and Air Nuigini could not immediately be reached for comment.

A photograph published online by Radio New Zealand showed four men standing in front of the burning fuselage of the small plane, a Dash 8 with Air Nuigini livery, one of them holding a long stick and a roll of paper.

The violence was an “absolute disgrace,” Papua New Guinea Prime Minister Peter O’Neill said in a statement on his website on Thursday.

“Those involved will be detained by police and prosecuted,” he said, adding that extra security forces were being sent to Mendi.

In April aid workers bringing relief supplies following a huge earthquake were ordered out of the neighboring provincial capital, Tari, and the army sent in to try and rein in disputes.

Media said the rampage was triggered by the court decision handed down in Port Moresby.

“We’re not really okay,” Julie Sakol, a nurse at Mendi Hospital told Reuters by telephone. “At the moment we are just standing outside watching what will happen next.”