Seven people died in fighting in Papua New Guinea's Enga province last week, with warring tribes burning down at least 3000 homes, the local police commander says.
The trouble started when a drunken brawl broke out between members of the Kandep and Paiela tribes at a club near the Porgera gold mine.
Two people died in a shoot-out at the club early last week, Enga Police commander Joseph Tondop said.
Violence quickly escalated, with two more people killed the same day in a retaliatory attack, and a further three in a roadside ambush the next day, he said.
"There's just too many deaths and injuries and destruction of properties."
In the ensuing chaos, the members of the warring tribes set fire to the homes of thousands of people near the Porgera mine.
Most of these people were illegal miners living near the mine in temporary settlements, he said.
"Because there are many people involved, it's like a humanitarian crisis now," said Mr Tondop, who estimated between 3000 and 4000 people had been forced to flee.
"We are in the process of getting them evacuated or repatriated back to their properties they come from."
The police commander said the situation in Enga had normalised this week and roads were clear.
No arrests have been made, with police waiting on the outcome of an investigation.
Local media reported on Tuesday that Enga Police were appealing to local leaders to surrender suspects.
In May, as many as six people were killed in gunfire exchanges between Amala and Teremanda tribes in Enga.