Living just two miles from an ancient temple that is claimed by both Cambodia and Thailand, Lamun Faithet is no stranger to being on the front lines of conflict.

She knows the routine well. In the event of an attack, she would go to the bunker in her village in the Thai province of Surin. The village chief would be the emergency warning system. That was how it worked in 2011, when she was forced to flee during another bloody clash between Cambodia and Thailand.

But this time things feel different.

Ms. Lamun, 68, is now one of more than 131,000 people in Thailand who have had to evacuate their homes. She has spent the past four days at a university campus in Surin, where a makeshift evacuation site has been set up.

Ms. Lamun said her house was the closest one in Surin to Prasat Ta Muen Thom, the temple where Cambodian and Thai troops first exchanged gunfire on Thursday. (Thais call the temple Prasat Ta Muen Thom, while Cambodians call it Prasat Ta Moan Thom.) For the first time ever, Ms. Lamun said, she was considering moving out of her home permanently.

“I thought everything was settled then,” she said, speaking of the previous conflict, which lasted from 2008 to 2011. “I didn’t think it would happen a second time.”

In recent days, Cambodia and Thai forces have been fighting each other in one of the deadliest border clashes ever between the two Southeast Asian neighbors. Since Thursday’s attacks, at least 34 people have died. In Cambodia, 35,000 people have fled their homes.