The NFL has a no-gun policy that could be threatened at CenturyLink Field by proposed legislation in Washington State. (Scott Eklund/AP)

Legislators in the state of Washington have proposed a bill that would allow fans to bring guns into sports stadiums, including Seattle’s CenturyLink Field and Safeco Field.

The proposal would prevent public stadiums or the private entities that operate them, from banning people with a valid concealed pistol license from entering with a firearm. It’s a proposal that is at odds with NFL and Major League Baseball regulations.

“We haven’t seen the proposed legislation but we have a policy forbidding carrying a weapon into NFL stadiums,” Brian McCarthy, the NFL’s vice president of communications, said in an email Sunday morning to The Post.

The Seattle stadiums, home of the Seahawks and Mariners and Seahawks, are privately operated and the proposal would extend to private operators of public spaces, stadium authorities and public facilities districts. The bill was proposed by Republican representatives Matt Shea, David Taylor and Bob McCaslin.

The proposal comes at a time when fan violence is a rising concern for the NFL.

“If you are concerned about bringing your family to a game, then that is an issue,” said Amy Trask, a former executive with the Raiders who has served on the NFL’s security committee, told The Post’s Kent Babb this fall. “It’s not just an issue for one team; it’s an issue for all 32 teams. The teams know this. The league knows this.”

Arrest totals have trended slightly upward on a per-game basis since 2011, according to a Washington Post examination of police data from the past five seasons and the proposal came to light in the same week as video of a fight at Kansas City’s Arrowhead Stadium went viral.

Three people were arrested Thursday night when the Chiefs hosted the Oakland Raiders, a traditionally intense AFC West Division rivalry, in an important game for both teams. There were no reports of injuries, but video of the fight is ugly. (You can see it here; it contains profanity.)

Fans had been congregating in the parking lot — and drinking — since noon for the night game. “As any general rivalries go, some chirping going on throughout the game. And as the game goes on people in the stands and in the game in general continue to drink and get more drunk,” a fan identified only as Devin told Kansas City’s Fox affiliate. “It kind of kept on escalating to the point of what you saw in the video, the brawl.”

Should the proposed bill pass in Washington, it’s a possibility that guns could be added to an already combustible environment.