Protesters blocked a light-rail line carrying Super Bowl ticketholders to the stadium in Minneapolis on Sunday evening, prompting a string of arrests.

However, protests did not extend to the players, none of whom took to a knee during the national anthem - something that became a controversial feature of the past season.

A transit spokesman said buses were on standby to help ferry fans of the New England Patriots and Philadelphia Eagles to US Bank Stadium in good time despite the demonstration outside.

Howie Padilla said 17 people were arreested but no one was hurt in the protest, which blocked trains for about two hours ahead of the kickoff.

The activists said they were protesting against police brutality, as well as the light-rail trains being taken over by Super Bowl spectators rather than being available to ordinary citizens.