Three GOP lawmakers will be issued fines after defying rules that require masks on the House floor during the COVID-19 pandemic on Tuesday.

A Capitol official said that Republican Reps. Brian Mast (Fla.), Beth Van Duyne (Texas) and Mariannette Miller-Meeks (Iowa) will be fined $500 after ignoring previous warnings.

Seven other Republicans will be issued formal warnings and would face $500 fines if they refuse to wear masks on the House floor again: Reps. Thomas Massie (Ky.), Marjorie Taylor Greene (Ga.), Lauren Boebert (Colo.), Chip Roy (Texas), Bob Good (Va.), Mary Miller (Ill.) and Louie Gohmert (Texas).

Any subsequent offenses would result in fines of $2,500 each.

The Republicans were staging a protest against the House floor mask mandate remaining in place despite new guidance from the Centers for Disease Control and Prevention (CDC) that people fully vaccinated against COVID-19 don't have to wear masks indoors or outdoors, except for certain crowded settings.

Greene posted a photo of herself and Massie, Miller and Rep. Ralph Norman (R-S.C.) on the House floor without masks, writing in a tweet: "#FreeYourFace Masks are oppressive and nothing but a political tool. End the oppression!"

But of all the Republicans facing fines or warnings, only Miller-Meeks confirmed in a CNN survey of all House members that she is vaccinated. Norman also confirmed in the survey that he is vaccinated.

CNN found that all 219 House Democrats said they were vaccinated, while only 95 of 211 Republicans did. Most GOP offices didn't respond to the CNN survey.

The Capitol's attending physician, Brian Monahan, said that the House floor mask mandate won't be lifted until all members and floor staff are fully vaccinated.

Speaker Nancy Pelosi (D-Calif.) announced in late July that masks would be required on the House floor due to dozens of GOP lawmakers refusing to wear them while the CDC was still recommending for everyone at the time. Gohmert was among those Republicans and later tested positive for COVID-19, prompting concern from other lawmakers who were in proximity to him.

House Democrats voted in January to institute the fines after several Republicans declined to wear masks while lawmakers were packed together in a secure room during the Jan. 6 insurrection.

Democrats also established fines for noncompliance with security screenings to enter the House chamber, after several Republicans also refused to go through the metal detectors installed outside the doors after Jan. 6. Fines for failing to undergo security screenings begin at $5,000 for the first offense and $10,000 for the second.

Earlier Tuesday, Rep. Virginia Foxx (R-N.C.) became the fourth House Republican issued a fine for failing to complete a security screening before entering the chamber.

The other lawmakers issued metal detector fines are Gohmert, Rep. Andrew Clyde (Ga.), Rep. Hal Rogers (Ky.) and House Majority Whip James Clyburn (D-S.C.).