Regal Entertainment Group, the largest movie theater chain in the U.S., has started checking bags of cinemagoers as a safety measure, following two theater shootings in the country this year. The rule applies to all its movie theaters across the U.S.

It is not known when the frisking process began at Regal Cinemas. However, local news networks reported that bags of people in Florida, Ohio, Texas and Virginia were checked earlier this month, the Associated Press reported Wednesday. The company, headquartered in Knoxville, Tennessee, functions about 570 theaters across America.

According to the company's website, "backpacks and bags of any kind are subject to inspection prior to admission.”  

"We acknowledge that this procedure can cause some inconvenience and that it is not without flaws, but hope these are minor in comparison to increased safety," it adds.

Earlier this month, National Amusements Inc.'s Showcase chain, which operates about 30 theaters in the northeastern U.S., banned backpacks and packages and said that it reserves the right to inspect purses and bags. The checking procedure will be in place "for the time being," it reportedly said.

For years, sports events and concerts have followed similar measures.

In July, a gunman shot two women dead and later killed himself at a theater in Lafayette, Louisiana. The following month, a man attacked moviegoers with pepper spray, a hatchet and a pellet gun at a theater near Nashville, Tennessee. He was later shot down by police. This year's shootings took place nearly three years after James Holmes, who was handed down life imprisonment earlier in August, killed 12 people at a Colorado movie theater.