GEORGETOWN, Texas (KXAN) — Two Round Rock schools were the latest to respond to threats on social media this week. CD Fulkes Middle School and nearby Claude Berkman Elementary went into “lockout” mode as a precaution as Round Rock Police investigated a social media threat Thursday. Round Rock ISD said it has not found evidence of the threat.

When in lockout, no one is allowed into the building. Students and staff stay inside, but classes continue as usual.

The Georgetown Police Department is also investigating “reported threat situations” Thursday at Georgetown High School, including a student with a water gun on a bus and a threatening list.

GPD said a student brought a “water gun that looked realistic” on a school bus. It has the gun and student, it said.

It’s also interviewing two students it believes are connected to an “alleged hit type list.”

“We always take these type of incidents seriously and respond promptly and act accordingly,” GPD said.

Since the elementary school shooting in Uvalde Tuesday that killed 19 students and two teachers, Central Texas schools have increased security. They’ve also investigated local threats.

Authorities removed a Taylor ISD student from class Wednesday after they made a “threatening comment” in class, a district letter sent to parents said.

A student at Bastrop Middle School wasn’t allowed to return to campus Thursday for the final day of school after making a threat Wednesday, according to a letter sent to families from the BMS principal.

The letter said students heard the comments and reported them to an adult who turned the information over to administration and police.

Manor ISD is only allowing essential visitors to enter its schools. The Manor Police Department said it detained four people as it investigated two threatening posts on social media. One was of a hunting rifle and a male voice saying “F— Manor” that was sent to several middle school students. Another photo sent on Snapchat showed a “female holding a weapon” with the words “Manor Got Some Coming.” It added there have been no specific threats made.

“We know that the last few days have been a tragedy for Uvalde, the State of Texas, and our Nation. Most of us at the Police Department are also parents so we like you share in the grief, the concern, and the fear. This is why you have seen a greatly increased police presence in the schools over the last several days,” GPD said.