The mother of Trayvon Martin, a black teenager who was killed by a neighbourhood watch volunteer in 2012, has announced she is running for office in Miami.

Sybrina Fulton, who became an activist against gun violence following her son’s death, will enter the race to join the 13-member board of Miami-Dade County commissioners.

Ms Fulton said she would continue working to end gun violence, the Miami Herald reports.

She will challenge Miami Gardens mayor Oliver Gilbert for the seat, which is up for grabs in 2020 because of term limits.

Trayvon’s parents head a foundation and have been recognised for their work on gun reform and social justice.

In pictures: Protests over the verdict in the trial of George Zimmerman Show all 7 1 /7 In pictures: Protests over the verdict in the trial of George Zimmerman In pictures: Protests over the verdict in the trial of George Zimmerman Martin1.jpg Demonstrators at a rally for Trayvon Martin at Union Square in New York (Peter Foley/EPA) In pictures: Protests over the verdict in the trial of George Zimmerman Martin2.jpg Demonstrators chant as they march through the streets of Atlanta (David Goldman/AP) In pictures: Protests over the verdict in the trial of George Zimmerman Martin3.jpg A demonstrator wears a hoodie during a protest in Atlanta (David Goldman/AP) In pictures: Protests over the verdict in the trial of George Zimmerman Martin6.jpg Police officers work to extinguish a fire during a protest n Oakland, California early on Sunday morning (Anda Chu/AP) In pictures: Protests over the verdict in the trial of George Zimmerman Martin7.jpg A demonstrator talks with police officers as people gather in Los Angeles (Jason Redmond/Reuters) In pictures: Protests over the verdict in the trial of George Zimmerman Martin4.jpg Vistors view a shrine which honors Trayvon Martin in Goldsboro, Sanford, Florida (Scott Olson/Getty Images) In pictures: Protests over the verdict in the trial of George Zimmerman Martin5.jpg Worshippers at the Middle Collegiate Church hold prayer services wearing hoodies in New York (Keith Bedford/Reuters)

Trayvon was unarmed when he was shot dead by neighbourhood watch volunteer George Zimmerman in 2012.

Mr Zimmerman had followed the 17-year-old and told a 911 dispatcher he looked like a “real suspicious guy”.

He was later acquitted on the grounds of self-defence.

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Mr Zimmerman was also arrested on suspicion of domestic violence in 2015, but was not charged after the alleged victim withdrew her claims.

He sparked outrage in 2016 when he auctioned the gun he claimed was used to kill Trayvon for $250,000 (£184,000).