US gold medallists at Pan American Games face sanctions over anti-Trump podium protests

Gwen Berry stunned the crowd when she raised a clenched right fist on the podium and bowed her head as the US national anthem closed her gold medal ceremony for the women's hammer.

The 30-year-old's protest on Saturday -- which she told US media was aimed at "extreme injustice" - echoed the iconic raised fist protest of US sprinters Tommie Smith and John Carlos at the 1968 Olympics in Mexico.

On Friday, two-time Olympian fencer Race Imboden, 26, set the tone after 'taking a knee' as his team celebrated gold in the team foil event.

He was the latest US sports star to follow NFL quarterback Colin Kaepernick, whose kneeling protest during the US national anthem before NFL games in 2016 became a national issue.

"We must call for change. This week I am honored to represent Team USA at the Pan Am Games, taking home Gold and Bronze," tweeted Imboden.

"My pride however has been cut short by the multiple shortcomings of the country I hold so dear to my heart. Racism, Gun Control, mistreatment of immigrants and a president who spreads hate are at the top of a long list.

"I chose to sacrifice my moment today at the top of the podium to call attention to issues that I believe need to be addressed. I encourage others to please use your platforms for empowerment and change."

Imboden had already staged a similar kneeling protest at the 2017 Fencing World Cup in Egypt.

Olympic athletics legend Carl Lewis, who had been attending the Pan American Games at the invitation of Lima organisers, had also taken the opportunity to slam Trump last week.

"We have a president who is racist and a misogynist, who doesn't value anybody but himself," said Lewis, who was asked to weigh in on the issue of gender equality in sport.

"My mother was a pioneer. My parents were teachers and they taught us that everyone deserves the same opportunities," said Lewis, who counts nine Olympic gold medals among his 10 total.

"Of course I'm for (equal pay) in athletics. We shouldn't even be talking about it.

"We have to fight for people's rights and love each other."