Yakima police arrested a 25-year-old transient woman who they say threatened to kill family members and herself, prompting a brief lockdown of a West Valley elementary school Wednesday.

Police went to the 7700 block of Westbrook Avenue after the woman’s mother said she was threatening to kill her, the woman’s sister and then herself, and that she had a gun, according to a probable cause affidavit. She was at her grandmother’s house in West Valley when she made the threats, the affidavit said.

Dispatchers called the grandmother, who said the woman had a gun in her pocket, according to the affidavit. When officers arrived in the area, the grandmother said she had locked the woman out of the house, and she was heading west on Westbrook Avenue, the affidavit said. She also said the woman was pregnant and had threatened to kill the unborn child.

Officers found the woman on the grounds of Yakima Valley Community Church and, after negotiations by phone, she surrendered to officers, police said.

During the incident, Wide Hollow STEAM Elementary School was placed on lockdown for three minutes, according to the district and police.

Officers found a black BB pistol that resembled a semiautomatic pistol in her purse, the affidavit said.

She was booked into the Yakima County jail on suspicion of felony harassment. Yakima County Superior Court Judge Richard Bartheld released the woman under the court’s pretrial release program.

Reach Donald W. Meyers at dmeyers@yakimaherald.com or on Twitter: donaldwmeyers, or https://www.facebook.com/donaldwmeyersjournalist.