CANTON, Ohio (AP) — The NFL will begin its new clear bag policy for fans this weekend at the Hall of Fame inductions and game.

For security reasons, fans can no longer bring backpacks or large bags into stadiums. The NFL is ratcheting up its safety measures in the wake of the Boston Marathon bombing.

The only bags that can be taken into game venues are clear plastic, vinyl or PVC that doesn’t exceed 12 inches by 6 inches by 12 inches, including one-gallon clear plastic freezer bags.

NFL security director Jeffrey Miller says a secondary perimeter will be set up outside Fawcett Stadium, site of the inductions and the first preseason game, in which Miami plays Dallas. Fans will be reminded of the new policy, and the league plans to make acceptable bags available for fans before they line up to enter the stadium.

The regulations are posted at nfl.com/allclear.