Tens of thousands of protesters have rallied across the US calling for tougher gun laws following the latest two mass shootings at a Buffalo supermarket and an elementary school in Uvalda, the BBC reported.

US President Joe Biden echoed the protests, calling on Congress to pass gun safety legislation based on common sense. Regardless, the chances of legislative change are likely to be crushed by the Republicans.

Nineteen children and two adults were killed in a May 24 shooting at Robb Elementary School in Uvalda, Texas.

This attack, and an attack in Buffalo, New York a few days earlier that killed 10 people, led to renewed calls for gun control measures in the US.

The gun-safety group March for Our Lives, founded by survivors of the 2018 Parkland school shooting in Florida, previously said there would be about 450 rallies across the country, including Washington, New York, Los Angeles and Chicago.

The group said it would not allow politicians to sit on their hands while people continued to die.