Fighting on the Thai-Cambodian border extended into a third day and new flashpoints emerged on Saturday as both sides said they had acted in self-defence in the border dispute and called on the other to cease fighting and start negotiations.

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.

More than 100,000 people have been displaced in the deadliest conflict between the two nations in 14 years. Thailand’s acting prime minister warned on Friday that clashes with Cambodia over a border dispute “could develop into war” as the deadliest fighting between the two countries in years extended into a second day.