Citigroup (C), one of the country's biggest banks, says it will no longer do business with those who don't adhere to its new policies on selling firearms.

Citi will require its clients to refrain from selling guns to those who have not passed a background check or who are not yet 21. It also prohibits them from selling bump stocks and high-capacity magazines.

The policy applies to bank customers who offer Citi-branded credit cards, borrow money or use other Citi services.

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The rules mirror restrictions set up by Walmart (WMT) and other major retailers, and come as some major companies move to distance themselves from the National Rifle Association. Another financial firm, First National Bank of Omaha, in February stopped producing credit cards for the NRA. More than a dozen companies also have ended discount programs fo members of the trade group, which has lobbied against more stringent gun control regulations.

"As the weeks pass after the most recent mass shooting, it appears we are stuck in the same cycle of tragedy and inaction," Ed Skyler, a Citi spokesperson, noted in a company blog post. "As a society, we all know that something needs to change. And as a company, we feel we must do our part," he added.

The Brady Campaign to Prevent Gun Violence, an advocacy group, called on lawmakers to take notice of Citi's policy change.

"We give a shout-out to Citigroup and all the other responsible businesses that have been more responsible than Congress in taking steps to prevent gun violence," Kris Brown, co-president of the Brady Campaign, said in an emailed statement.

"As an avid outdoorsman and responsible gun owner, I know that some will find our policy too strict while others will find it too lenient," Mike Corbat, Citi's CEO, said Thursday in an internal memo to employees.

Citi has begun discussions about the policy with its small business, commercial and institutional clients. For those that choose to opt out, Citi will "work with them to transition their business away from Citi," said Corbat.

Citi has "few relationships" with companies that make firearms, and Citi plans a conversation with them to ensure they only sell to retailers that adhere to the new policy.

A spokesperson for JPMorgan Chase (JPM), the nation's largest bank, declined to comment on the policy shift by Citi.

Another change in policy targeting gun violence was announced this week by YouTube.

Starting in April, it will prohibit content that promotes the sale of firearms and accessories such as bump stocks. It will also ban videos offering instructions on how to put together guns or outfit the weapons to make them deadlier.

Citi and YouTube made their moves days before the March for Our Lives rally, which is set for Saturday and organized by survivors of the Florida high school shooting on Feb. 14.