A day after a gunman shot dead 19 children and two adults, police have stormed another Texas school after a teen was seen approaching with a rifle.
Police in Dallas, roughly 600km northeast of where 18-year-old Salvador Ramos opened fire at a Uvalde school, arrested a juvenile student with guns at Berkner High School.
Witnesses say they saw a male walking along a main road in the suburb of Richardson carrying a rifle before calling police.
Officers rushed to the scene and located the suspect inside the school, identifying him as a juvenile student. They discovered a replica rifle and AK-47 pistol in a nearby car, Richardson Police said in a statement.
He has been charged with unlawfully carrying a weapon in a weapon-free school zone.
"The Richardson Police Department would like to remind the public of the importance to report suspicious activity," police said.
"We recognise the vigilant awareness and actions of the person who initially called 911."
Gun reform advocates Sandy Hook Promise, an organisation set up in the wake of the US's second deadliest school shooting, said a "potential tragedy" had been avoided.
Gun control debate escalates in Texas
The state's governor Greg Abbott is facing mounting pressure over his stance on gun control.
On Wednesday, he was accosted by his political rival Beto O'Rourke who told him the mass shooting in Uvalde was "on you".
Mr Abbott has served as governor of Texas since 2015 when he infamously tweeted he was embarrassed that California had more new gun purchases than Texas, and he called on Texans to buy more guns.
Do you have a story tip? Email: firstname.lastname@example.org.