LOS ANGELES (CBSLA) — Cinemark theaters will ban large bags beginning Thursday, citing security concerns.

The new policy bans anything bigger than 12 x 12 x 6.

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Managers at a theater in Chino say they’re not going to break out a tape measure to check — they’re just trying to improve safety and security.

Twelve people died when a gunman opened fire inside a Cinemark Theatre in Colorado in 2012.

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Customers are still divided.

“I think it would make a safer environment for those that would be attending the movies. But for me, I like to bring my water,” Gloria Galvez said.

“I think if it’s for safety, that’s great. But if it’s just because you’re afraid of people smuggling in pops and other food, then that’s a little drastic,” Sarah Landis said. “Because I use public transportation and I go to the gym in the same plaza, so it just makes sense to bring it all when I’m going to go.”

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Medical equipment bags and diaper bags are not included in the ban.