Tens of thousands of people demonstrated Saturday against gun violence across the US after a series of mass shootings in recent months.

The protests, which call for action on gun control, were organized by the March For Our Lives organization, which was founded by students who survived a mass shooting at a school in Parkland, Florida in 2018.

In Washington DC, demonstrators gathered at the National Mall area, carrying banners that read "Gun control now," "End gun violence," "Enough is enough," and "Protect kids not guns."

Mayor Muriel Bowser also addressed the crowd that gathered around the Washington Monument, asking for Congress to implement "common sense" gun laws to combat gun violence.

"It is common sense to ban assault rifles in our country," said Bowser.

She was joined by children who carried banners that read "Books not bullets" and "Kids for safe schools."

The nationwide demonstrations were in response to the latest school shooting in Uvalde, Texas and a deadly racist attack in Buffalo, New York.

An 18-year-old gunman entered an elementary school in Uvalde and killed 19 students and two teachers on May 24. Ten days before that shooting, an armed white man raided a supermarket in a Black-majority neighborhood in Buffalo and killed 10 people. Authorities called the Buffalo shooting a "racially motivated, hate crime."

US President Joe Biden has repeatedly urged Congress to pass stricter gun laws to reduce gun violence across the country. The House of Representatives passed this week "Protecting Our Kids Act," aimed at preventing gun violence.

The bill seeks to raise the age for buying automatic rifles from 18 to 21, among other measures.

In addition to the US capital, demonstrations also took place in New York, Los Angeles, Chicago, Boston and other cities.

At least 255 mass shootings have occurred in the US this year, according to non-profit tracker the Gun Violence Archive./aa