(Reuters) - Carolina Panthers quarterback Cam Newton weighed into the Charlotte unrest by wearing a T-shirt emblazoned with a famous quote from civil rights activist Martin Luther King Jr. ahead of his team's home game on Sunday.
The reigning NFL Most Valuable Player took the field for the pregame warmup wearing a black T-Shirt with a King quote on the back in white letters that read "Injustice anywhere is a threat to justice everywhere."
Newton's on-field statement at Charlotte's Bank of America Stadium came five days after a black man, Keith Scott, was fatally shot by a black policeman in Charlotte.
Demonstrations have been a constant for nearly a week in the North Carolina city and there was increased police presence outside the Panthers' stadium where protesters were marching as fans arrived for the game.
Newton, who usually eschews social comment, spoke about the incident last Thursday.
"I'm a firm a believer of justice. I'm a firm believer of doing the right thing," Newton told reporters.
"And I can't repeat it enough of just holding people accountable ... I am not happy with what or how the justice has been kind of dealt with over the years.
"The police brutality ... it's embarrassing to even talk about. When you sit up here and list the names, it's crazy to even think about how did this even happen and how do police who take a leave absence and still get paid."
Newton followed regular protocol during the playing of the U.S. national anthem before Carolina's game against the Minnesota Vikings.
The only player on either team spotted making a silent statement was Panthers backup safety Marcus Ball, who stood with his right arm raised and index finger extended.
Elsewhere, over a dozen NFL players made silent protests during the national anthem, in a continuing league-wide movement that shows no sign of waning.
San Francisco 49ers quarterback Colin Kaepernick started what has become a controversy when he began the gesture against injustice and police brutality by refusing to stand for "The Star-Spangled Banner" during preseason games.
In Jacksonville on Sunday, four Jaguars players raised their right hand during the anthem, the first time this season anyone from the team has not followed protocol.
Four Washington Redskins players also joined the protests by raising their right fist before their game at the New York Giants.
Denver Bronco Brandon Marshall kneeled during the anthem for a third straight game ahead of his team's game in Cincinnati.
In Miami, three Dolphins knelt for the anthem, while in Nashville four players from the home team Tennessee Titans raised a fist, and were joined by two players from the visiting Oakland Raiders.
(Reporting by Andrew Both in Cary, North Carolina; Editing by Frank Pingue)