SAN ANTONIO -- A girl's high school volleyball team was shocked to find a bloody deer carcass on their bus after a game against a rival.

Members of the Comfort High School Whitetail Deer volleyball team came across the remains of a dead deer after playing a game against Blanco High School.

A sister of a Comfort High School student said she believes students from Blanco High School placed the carcass on the bus as a prank.

"That is very inappropriate, I just couldn't believe it," Laura Lozano said. "(My sister) was just so surprised that they would do something like that."

Lozano said the rivalry between the two schools is deeply seated.

"We had actually beat them last year at their homecoming, so I guess that's where a lot of the rivalry really kicked in," she said.

Tasha Brieger, a former Blanco student, said she doesn't believe Blanco High School students pulled the prank.

"Blanco's a really close-knit town," she said. "We're pretty easy going, we get along with pretty much anybody and that doesn't sound like something we would do."

A letter of apology was sent to Comfort High School immediately following the incident.

The principal of Blanco High School said he's disappointed and made it clear to students that this type of behavior won't be tolerated.