At least a dozen people were killed after the two countries exchanged fire after simmering tensions over a border dispute boiled over on Thursday.

Armed clashes have broken out between Thailand and Cambodia in long-disputed border areas, rapidly escalating months-long tensions.

Thailand and Cambodia exchanged fire along their disputed border for a second day on Friday, officials from both countries said, with more than a dozen people reported killed and more than 135,000 civilians evacuated.

The Pheu Thai Party has dismissed allegations that the Thai-Cambodia border dispute stems from personal or political rivalries between the Shinawatra and Hun Sen families, instead attributing it to Phnom Penh’s dissatisfaction with Thailand’s aggressive crackdown on Cambodia-based online scam centres.

Thailand claims the ordnance was newly laid, but Cambodia says they are leftovers from a final stint of fighting during the murderous Khmer Rouge regime. Still, soon after the incident, both sides downgraded relations, expelled their neighbour’s ambassador and recalled embassy staff.