2:15 p.m. update: Threats made against Lake Travis High School have been determined to be unfounded, Principal Gordon Butler said in a letter to parents Thursday afternoon.

Additional law enforcement officers were on campus Thursday after 80 tips of a threat against the school were reported. But after an investigation of the tips, a review of social media, and interviews with students and staff, officials have found there was no direct threat to the high school, Butler said.

"Contrary to student conversations and social media activity, no weapons have been recovered, no arrests have been made, and at no time was our campus placed on lockdown," Butler said.

Earlier: Threats of violence and the use of weapons at Lake Travis High School has led to an increase in law enforcement officers on campus Thursday, Lake Travis school district officials said.

Lake Travis High School Principal Gordon Butler sent a letter to parents and guardians Thursday morning that said the district had received an influx of reports that threats were being made against the school.

"This information has been reported to law enforcement officials who are presently investigating the matter," Butler said in the letter.

Students, parents and community members have reported threats to the district through a tip line and on social media, district spokesman Marco Alvarado said. The threats have involved weapons and could be coming from anyone, he said.

Butler said the threats were not related to a student assault on a teacher that occurred at the high school earlier this week.

He said that students should report any information or suspicious activity to an adult.

"We're looking forward to a regular day of instruction at the high school," Alvarado said.