Photo: The Canadian Press

NFL players refuse to stand during U.S. national anthem.

UPDATE: 10:40 a.m.

NFL players used the U.S. national anthem to show their defiance to President Donald Trump's criticism, with an unprecedented number of players kneeling in protest and one team staying in the locker room.

Most teams in the early afternoon games locked arms in solidarity. At least three team owners joined their players.

More than 30 players knelt, the form of protest started last season by former San Francisco 49ers quarterback Colin Kaepernick. Kaepernick is now a free agent, and supporters believe teams have avoided signing him because of his protest.

The Pittsburgh Steelers remained in the locker room as the national anthem played before their game with the Chicago Bears. Coach Mike Tomlin stood by himself on the sideline.

How each team would observe the national anthem emerged as the centre of attention on this NFL Sunday in the wake of Trump's critical remarks toward players who don't stand for the anthem.

Tomlin had said before the game that Pittsburgh's players would remain in the locker room and that "we're not going to let divisive times or divisive individuals affect our agenda." Tomlin added that the Steelers made this choice "not to be disrespectful to the anthem but to remove ourselves from this circumstance. People shouldn't have to choose."

ORIGINAL STORY: 8 a.m.

The owners of the Baltimore Ravens, the Super Bowl champion New England Patriots and other teams on Sunday joined a chorus of NFL executives criticizing President Donald Trump's suggestion that they fire players who kneel for the national anthem.

The statements, from Patriots owner Robert Kraft and Ravens owner Steve Bisciotti, contrasted a morning tweet from Trump and further escalated the political drama of the league's game day, which was expected to be one of the most-watched for non-sporting reasons in years.

Bisciotti said he "100 per cent" supports his players' decision to kneel during the national anthem. At least seven of them did, joined by more than a dozen Jacksonville Jaguars, before the teams played at Wembley Stadium in London.

Kraft, who has been a strong backer of the president, expressed "deep disappointment" with Trump and said politicians could learn much from the unifying spirit of a competitive, team-oriented enterprise like football.

"Our players are intelligent, thoughtful, and care deeply about our community and I support their right to peacefully affect social change and raise awareness in a manner that they feel is most impactful," Kraft said in a statement.

Quarterback Colin Kaepernick started the kneeling movement last year when he played for the San Francisco 49ers, refusing to stand during "The Star-Spangled Banner" to protest the treatment of black people by police. Kaepernick became a free agent and has not been signed by a new team for this season.

Without identifying Kaepernick, Trump aimed a Friday talk at a Huntsville, Alabama, rally at those players who have knelt for the anthem.

"Wouldn't you love to see one of these NFL owners, when somebody disrespects our flag, you'd say, 'Get that son of a bitch off the field right now. Out! He's fired,'" he said to loud applause.

Again in a Sunday morning tweet, Trump urged his supporters to take action: "If NFL fans refuse to go to games until players stop disrespecting our Flag & Country, you will see change take place fast. Fire or suspend!"