GRAND BLANC, MI - While thousands of students across the nation walked out of their schools today in a protest of gun violence, Grand Blanc High School locked its classroom doors to bar its students from taking part.

Instead, the district encouraged students to write letters to elected officials in support of gun reform.

Marking the one-month anniversary of the fatal school shooting in Parkland, Florida, the #Enough! National Walk Out took place in schools across Michigan and the country at 10 a.m. on Wednesday, March 14. Organized by Women's March Youth Empower, many protests lasted 17 minutes - one minute for each of the victims in the Valentine's Day massacre at Marjory Stoneman Douglas High School.

But at 9:55 a.m. at Grand Blanc High School, administrators put the school in "secure mode." Students said all classroom doors were locked until the end of third period at 10:23 a.m.

In an email to students and parents, GBHS Principal Michael Fray said he and the school's resource officer decided on the security provision "in the interest of maintaining a safe school environment."

MLive-The Flint Journal could not immediately reach Fray nor Superintendent Clarence Garner for comment on the matter.

According to a statement from Grand Blanc City Police, the decision to put the school in "secure mode" was made after the school's resource officer received information from student that "someone would get hurt" if the walkout took place.

Please feel free to post your opinions about the actions taken today to secure the students and the school, but please do not post any personal attacks against someone who may have a differing opinion. Posted by City of Grand Blanc Police Department on Wednesday, March 14, 2018

"We maintain a belief that our students should be allowed the opportunity to have their voices heard on the topic of school safety," Fray's email said. "With that said, we remain steadfast in our belief that maintaining a safe and orderly school environment is our number one responsibility."

At 10 a.m., the high school emailed a list of elected officials for students to contact to "advocate a solution to the school safety debate."

"As many of you know, there is a nationally advertised Student Walkout for today, March 14 at 10:00am. We are NOT supporting participation in this walkout and any attempt to walkout will be considered skipping class," Fray's message to students read. "We do believe in your right to assemble and are working with a group of students to provide an organized and safe walkout event on April 20th."

After the secure mode was lifted, around 100 students filled the hallway in front of the school's main office for a 17-minute sit-in, instead.

at first a 17 min peaceful protest was supposed to take place at 10am then we got put in “secure” mode to stop the students who wanted to be part of this movement. pic.twitter.com/3cikMD7Qje — lena! (@lenakk21) March 14, 2018

However, some Grand Blanc students say they feel their rights were violated by the school's decision to lock them into their classrooms during the protest period.

"Going into secure mode like that, everyone went into fear because we thought there was an actual threat," said junior Lena Kas-Mikha, who had planned to participate in the walkout. "Me, personally, and my friends, we were upset because we felt like we were lied to ... when we found out it was just to stop the walkout."

Senior Caroline Lostutter said she hadn't planned to participate in the school protest, but took to Twitter after the lock-in was announced to voice her frustration with the school's handling of the matter.

"It felt like an abuse of power, not to give the choice to people who wanted to participate," Lostutter said. "I think their intentions were good in trying to keep students safe, but they should have sent out hall monitors or something if they were worried about it They didn't handle things in the best way and it kind of spiraled."

I wasn’t planning on participating in the walk-in HOWEVER I think it is ridiculous that a school would put their students in SECURE MODE to keep them from assembling and taking a part in something they feel strongly about. #traditionofexcellence — Caroline Lostutter (@c_lostutter) March 14, 2018

In a post that has since been removed from Facebook, Grand Blanc Community Schools took to social media in the afternoon to announce its decision to put the high school into secure mode "in the interest of maintaining a safe school environment."

Other students have taken to Twitter to criticize and comment on the decision:

Regardless of my opinion on guns & issue in the US right now. Citizens of the United States have a right to assemble. Locking students in class does not do anything but infringe on that right and show kids that when they want to make change. They can’t trust authority for help. — Max (@MaxJPattillo) March 14, 2018

Literally Grand Blanc high school just continues to disappoint me and I don’t even go there anymore. How are you about to stop the students from a peaceful protest by holding them in a lockdown illegally? Saying there’s a threat when there’s not! — Abbey🌻 (@AbbeyBarnhart1) March 14, 2018

They shut the school down in secure mode so we couldn’t walk out today even though they “applaud those that are organizing events” and “believe in your right to assemble” #gbhs #walkout — Kassi Perez (@kassiperez_) March 14, 2018

does the school not realize the assembly would have been smaller but since they stopped our voice all we did was spread it more — hadley (@Hadleyep) March 14, 2018

I’m sure you’re all asking; “Why are we in secure mode?” One of two reasons:

1) The administrators have acknowledged the rumors of threats and want to keep us SAFE

2) GBHS wants to keep us SILENT. If this is the case, WE WILL NOT BE SILENT. WE WILL STAND TOGETHER. — dev (@softgoththot) March 14, 2018