HOUSTON -

A school district increased security Friday because of a rumor about a threat of a mass shooting.

Humble Independent School District officials said there was a rumor posted on a personal blog that there would be a shooting at a gas station in Kingwood on Friday.

School district officials said the blog posting did not mention any schools, but officers decided to increase their presence at the district's 13 schools as a precaution.

The schools have also moved outdoor physical education classes inside.

"I'm not worried," one parent said. "It's just a rumor going around. Everyone's safe and we got out precautions take care of, so we're good."

School district officials stressed that the threat was not made against any Humble ISD campuses.

The New Caney ISD also has a campus near the Kingwood area, Kings Manor Elementary, 21111 Royal Crossing Drive, and has implemented similar measures there. A private school in the area, St. Martha's, took similar precautions.

The FBI is investigating the threat.

"We are not able to discuss any specific details of any ongoing investigations at this time. But we remain ever vigilant, and take each and every threat that is brought to our attention very seriously. We work very closely with our local, state, and other federal partners to mitigate any threats. At this time we are not in possession of any substantiated information which indicates anyone within our territory is in any danger at this time," a statement from the FBI read.