Arlington Lamar High School was locked down for several hours Tuesday after a school resource officer was told there may be a weapon on campus.

According to the Arlington Police Department, at about 8:40 a.m. a student told the officer that another student may have brought a handgun to school.

The school was then placed on lockdown while the claim was investigated. Arlington police said officers, including a K9 officer, searched the school room to room.

"As a precaution, we have taken several steps to investigate this matter. We do not have any confirmation at this point that a gun was brought onto the campus and will provide further details as the investigation unfolds. The safety of our students is the highest priority," said Tiara Ellis Richard, with the Arlington Police Department, in a statement to NBC 5.

Late Tuesday morning, police addressed parents and media outside the school and confirmed that no weapon had yet been found on campus and that the investigation was ongoing and that was why there was still such a strong police presence at the school. The department later uploaded video of that statement to YouTube.

The district eventually lifted the lockdown when no weapon was found. According to a statement by the school district, police are confident the person believed to have the weapon was not on campus.

Parents Anxious Over Information Process

Anxious parents grew frustrated when information did not get to them as quickly they would have liked.

“I got a message from my daughter in Chicago that the school is on lock down. The school has not contacted us, they don’t have any violence incident plan set up or anything so I’m very upset about that,” said Gina Hampton, the mother of a Lamar student.

“I’m a little surprised there wasn’t a call out,” said another parent, referring to the Arlington Independent School District not calling parents to alert them of the lock down.

“I understand parent’s frustration; I understand how frustrated they are right now,” said Amy Casas, who stressed that the district’s top priority was the students.

AISD did post updates on their website and Facebook page.

“We want to make sure we’re getting the correct information out as quickly as possible and we’ll never be as quick as some would like. But in maintaining the integrity of the investigation we really got to make sure that everything is on spot and on target when we’re searching the school and we don’t prematurely release information that could jeopardize the investigation,” said Sgt. Christopher Cook with the Arlington Police Department.

NBC 5's Mola Lenghi contributed to this report.