ANGLETON, Texas (AP) — Authorities reported that a Texas mother facing charges of murder after shooting her four children over the weekend, resulting in the death of two.

The 31-year-old is accused of two counts of murder and two counts of aggravated assault with a deadly weapon, as stated by Brazoria County Sheriff Bo Stallman. She is detained with a bond set at $14 million.

On Saturday, two children aged 13 and 4 were killed by gunfire inside a vehicle. The other two children, aged 8 and 9, were transported by medical helicopter to a hospital near Houston and are in “stable condition,” according to Stallman.

The children’s mother called 911 to alert authorities after the shooting, Stallman said. Authorities recovered a weapon at the scene, he added.

“A tragedy like this defies understanding, but we are committed to achieving justice for these children,” Stallman expressed.

The mother is a resident of Montgomery County to the north of Houston, he said.

The incident occurred in Angleton, a city with a population of approximately 19,500, serving as the county seat of Brazoria County, roughly 45 miles (70 kilometers) south of Houston.