ROUND ROCK, Texas (KXAN) — Round Rock ISD said McNeil and Round Rock High School were on lockdown Thursday afternoon for approximately two hours while authorities “investigated an anonymous threat.”

According to a letter sent to parents, the lockdown was initiated at 3 p.m. while RRISD’s police department investigated the alleged threat.

The district said on social media around 4:50 p.m. that the lockdown had been lifted.

“All students and staff were kept safe and secure throughout the entire process,” the social media post said.