Nike Inc. (NKE.N) pulled Fourth of July sneakers from stores because they had a “Betsy Ross Flag” that some people view as offensive, pulling the sports apparel maker once again into America’s culture wars.

Former NFL quarterback Colin Kaepernick was among the people who asked Nike to remove the shoe, according to the Wall Street Journal. The Air Max 1 USA was intended as a celebration of U.S. Independence Day, with a flag that featured 13 white stars in a circle on the heel.

The design was created during the Revolution and is often called the Betsy Ross Flag. Some far-right groups have claimed the flag as a symbol of their cause, and it has also been criticized as evocative of an era when slavery was still predominant in the U.S.

“Nike has chosen not to release the Air Max 1 Quick Strike Fourth of July as it featured an old version of the American flag,” said Mark Rhodes, a spokesman for the company, in an email Monday.

It’s the second time in two weeks that company has had to pull shoes out of political concerns. Last week, Nike withdrew from China a line of limited edition shoes after the Japanese designer behind them posted in support of the Hong Kong protests against a proposed extradition bill.

Nike has asked merchants to return the shoes, without saying why, the Journal reported, citing people it didn’t identify. The shoes aren’t available through the company’s apps or websites, the newspaper said.

Kaepernick, who endorses Nike products, contacted the company after the shoes were posted online, saying the flag is an offensive symbol because of its connection to an era of slavery, the newspaper said.

The former 49ers quarterback hasn’t played since 2016, when he began kneeling during the national anthem to protest racial inequality. Last year, Nike made Kaepernick the face of an advertising campaign while he was engaged in a dispute with the league. Nike last week reportedquarterly sales rose four per cent to US$10.2 billion.

The shares were little changed at US$85.33 in early trading, not far from their record closing price of US$89.20 on April 18.

--With assistance from Eben Novy-Williams and Rachel Chang