EDISON - Billboards calling on Gov. Chris Christie to denounce presidential candidate Donald Trump are popping up across New Jersey.

Bridges Over Politics for New Jersey, a new nonprofit advocacy group, said Friday that it has spent six figures for about a dozen billboards and digital ads across the state.

The billboards are in Bergen, Hudson and Mercer counties. Christie endorsed Trump for president after ending his own campaign.

The group is headed by Aaron Keyak, a one-time aide to former Democratic U.S. Rep. Steve Rothman. The group's donors are not public.

One of the ads shows Trump with Christie behind him. The text asks Christie to "stand up to racism and bigotry."

Christie's office was critical. Spokesman Brian Murray says it's sad anyone would give the billboards a second look.

The Associated Press wire services contributed to this report.