Dozens of local councillors from districts in Papua New Guinea's Western Highlands have signed a series of guidelines on tribal fighting.
The rules were signed in the presence of hundreds of people in Tambul-Nebilyer district last week, after being drafted with the support of the International Committee of the Red Cross.
The region has been plagued by tribal fighting in the aftermath of a devastating magnitude 7.5 earthquake in February, which has forced aid agencies to suspend their efforts in some areas.
The organisation's deputy head of mission in PNG, Ahmad Hallak, was at the signing ceremony.
He said the rules stem from customary rules that set out guidelines on how tribal fighting was conducted in the past.
"They're very similar to the spirit of the international humanitarian law," he said.
"Avoiding the targeting of civilians, the destruction of civilian property during tribal fighting. So it doesn't necessarily prohibit tribal fighting per se, but it does regulate tribal fights that do take place."
Mr Hallak said the signing of the rules appeared to be well received in a district which had experienced brutal tribal fighting in the past.
"It remains to be seen how effective this will be, and to what extent it will reduce the consequences of future tribal fights, if they do occur," he said.
"But it seemed to be received quite well."
Meanwhile, he said the ICRC would continue its efforts to assist people in Highlands areas impacted by February's 7.5 magnitude earthquake in the region.
Tribal fighting has hampered relief and recovery efforts in Hela province in particular, but Mr Hallak said his organisation was committed to helping the many communities in need.
"We were here before the earthquake and we'll be here long after the earthquake response has ended."