Two hunters who were questioned in connection with the shooting of two middle school students were released today, however the third, who police said is an illegal immigrant, will remain in custody.

Hidalgo County Sheriff Lupe Trevino said the two men were doing target practice and could have been in the line of fire to hit the Harwell Middle School students 800 yards away.

The illegal immigrant was trespassing on the property and had an assault rifle, Trevino said.

The students, ages 13 and 14, were struck around 4:45 p.m. Monday while trying out for the school basketball team in the school's parking lot, which is adjacent to two parcels of brush land that are popular with hunters.

One was hit in his right armpit and the other was struck in the right side of his upper torso.

Gilbert Tagle, spokesperson for the Edinburg Consolidated Independent School District, told ABCNews.com the two students are in stable condition.

 "One went through an operation to remove a bullet," Tagle said. " It's in control of the sheriff now and he'll try to match it up with the guns the hunters were using."

The school has since beefed up security and has grief counselors on site for students and staff.

Tagle said the school board will meet tonight to discuss erecting a cinder block fence to protect the students from any errant bullets.

"This seems like a freak hunting accident," he said. "And if it was their bullet, it traveled a pretty good ways."