First black female sworn in as San Francisco mayor

London Breed Wednesday was sworn in as the first African-American new female mayor of San Francisco, a major tourist city on the U.S. west coast, amid challenges ranging from homeless crisis, skyrocketing housing prices and a widening income gap between the rich and poor.

The 43-year-old San Francisco native succeeded former Mayor Ed Lee, who died unexpectedly last December, as the 45th mayor after she won 50.55 percent of vote in a tight race for the mayoral office last month.

Breed took oath outdoors on the steps of City Hall in a public ceremony in downtown San Francisco that was watched by around 1,000 audience.

The first black female mayor, who grew up in a poor family in the Western Addition neighborhood in the city, promised to address pressing problems afflicting the city, including housing shortage.

"We will build more housing" and change the "politics of no to the politics of yes," she said.

She promised to be a mayor of everyone, a main theme of her campaign in the past six months, and help immigrant families, small businesses, public housing projects and efforts to create a better social security order.

"We have so much to do: re-envision our transportation system to make biking safer and improve Muni, invest in our parks, rebuild the seawall, reform our criminal justice system, support small business, and protect all our communities from what comes from Washington D.C.," she tweeted after her inauguration ceremony.

She said she would try her best to help homeless population off the street and into care and shelter.

There were 7,500 people sleeping on the streets every night, said Jeff Kositsky, director of the city's Department of Homelessness and Supportive Housing last year.

Breed served as the president of the San Francisco Board of Supervisors and briefly acted as interim mayor of the city after Lee's death in December last year.

Lee was the first Chinese American mayor who had served the city for many years.