ZAMBOANGA, Philippines (AP) — An army commander says at least eight people have been killed in a clan war triggered by the sale of a car in the southern Philippines.

Army Col. Daniel Lucero says sporadic gunbattles raged Friday and Saturday between a Muslim clan led by Arimao Asum and two rival families in Lanao del Sur province’s Sultan Dumalondong town.

Lucero said Monday that an unpaid debt from the car sale led to a killing in 2001, and was followed by retaliation by both sides that culminated in the weekend clashes.

Clan wars over money, land, politics and old scores are a key security concern in the south, in addition to decades-long Muslim insurgencies.