It happened at Trinity Gardens Park near Kashmere High School just after 1:30 p.m. on Wednesday.
Houston Police Asst. Chief Patricia Cantu said both the teens, who are 16 and 17 years old, were shooting at each other.
The 16-year-old was shot three times in the abdomen, once in the arm and once in his thigh. He was rushed to the hospital where he's in critical condition but remains stable.
Cantu said four of his friends were able to take him to Kashmere High School for help. They were also able to provide authorities with the shooter's name.
The shooter, according to police, is a student at the school. It's unclear if he was injured.
The victim, however, is not a Kashmere High student.
It's unclear what led to the rivalry, but police believe it may be gang related.
As the investigation was unfolding, HISD issued a call to all Kashmere High School parents relaying the following message.
"Dear Kashmere High School parents:
Our campus is temporarily on lockdown as a precautionary measure while police are investigating suspicious activity in the area.
Our students are safe, our building is secure, and our instructional day continues normally and will dismiss at the regular time. We ask all car riders to please pick up students on Bennington Street.
If you have any questions, please contact our school at 713-636-6433."
At 4:30 p.m., the lockdown was lifted.
The incident remains under investigation.
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