Janet Jackson accepts the Ultimate Icon Award during the 2015 BET Awards in Los Angeles, California, June 28, 2015. [Photo/Agencies]

Rapper Sean "Diddy" Combs took a tumble, Janet Jackson made an emotional appearance, and the BET TV network paid tribute on June 28 to campaigners across the United States demanding better police accountability after a troubled year.

Combs fell through a hole in the stage at the BET Awards show during a 20th anniversary celebration of his Bad Boy record label that reunited hip-hop artists including Lil' Kim, Faith Evans and 112 in a celebration joined by Pharrell Williams.

Combs quickly got up and carried on with the performance, appearing unhurt.

The BET awards pay tribute to the leading black music, acting, sports and entertainment figures in the United States of the past year.

Current political events were never far away at Sunday's ceremony in Los Angeles. Actor Michael B. Jordan, star of the 2013 film "Fruitvale Station", gave a speech on behalf of the cable network recognizing the thousands of Americans who have marched and demonstrated over the deaths of young black men at the hands of police in the past 12 months.

"BET is shining a light on you for taking to the streets and insisting that black lives matter. We see you and applaud your unbreakable, unshakeable strength," Jordan said, referring to deaths in Ferguson, Missouri, Baltimore and New York.

In one of the most hotly anticipated moments of the almost four-hour ceremony, Janet Jackson was presented with the inaugural Ultimate Icon: Music Dance Visual Award.

Jackson, 49, announced last month that she would release her first album of new material since "Discipline" in 2008 and embark on her first world tour in four years.

"It's been a very long journey to this moment. My heart is so full," said Jackson, dressed in a white jump suit.

The youngest member of the Jackson family singing clan, Janet thanked her fans and her parents, Joe and Katherine Jackson, who were seated at the front of the Los Angeles arena.

In the main awards of the night, rapper Nicki Minaj won for best female hip-hop artist and Kendrick Lamar, who performed atop two graffiti-covered police cars, took home best male hip-hop artist.