An affiliate of the National Rifle Association in California is asking a federal judge to block a new law requiring background checks for people buying ammunition.

The California Rifle & Pistol Association on Monday asked U.S. District Judge Roger Benitez in San Diego to halt the checks and related restrictions on ammo sales.

Voters approved tightening California’s already strict firearms laws in 2016. The restrictions took effect July 1.

The gun owners’ association challenged the background checks in a lawsuit filed last year and is now seeking an injunction.

Benitez previously rejected the state’s attempt to dismiss the lawsuit.

Earlier this year, he struck down California’s nearly two-decade-old ban on high-capacity ammunition magazines. That triggered a week-long buying frenzy before he stopped sales while the state appeals his ruling.