At least 21 people including 19 children and two adults were killed after an 18-year-old gunman opened fire at an elementary school in Uvalde, Texas.
Texas Governor Greg Abbot identified the gunman as Salvador Ramos who was a resident of the town of Ulvade, 135 kilometres west of San Antonio.
It is unclear what motivated Ramos to carry out the attack. Reports say that an Instagram account linked to Ramos had a post which showed two automatic rifles. The 18-year-old was shot dead by police.
Before he attacked Robb Elementary School, Ramos allegedly shot his grandmother who survived and is receiving treatment.
After shooting his grandmother, Ramos crashed his car near the school and entered the school where he engaged in a gun fight with police officers and injured two.
The massacre at Robb Elementary is the deadliest school shooting in the US after the 2012 Sandy Hook school shooting where a 20-year-old man shot and killed 26 people including 20 children.
The Uvalde shooting comes 10 days after a white supremacist shot and killed 10 black people at a supermarket in Buffalo, New York.
A majority of students at Robb Elementary are Latino and are between the ages of six to ten. The school was set to break for summer vacations in two days.
To celebrate the upcoming summer break, the school had organised special themed dress days encouraging students to come dressed in fancy outfits.
CNN reported that many parents waited outside a civic centre late into the night to learn the fate of their children with some saying that they had to provide DNA samples to help authorities identify children.
In the aftermath of the shooting, US President Joe Biden called for "common-sense gun laws" to be passed in the US and attacked the pro-gun lobby for blocking measures to bring in regulations and reforms.
"I had hoped when I became President I would not have to do this again. Another massacre. Beautiful, innocent, second, third, fourth graders. And how many scores of little children who witnessed what happened -- see their friends die as if they're in a battlefield, for God's sake. They'll live with it the rest of their lives," Biden said at a press conference.
"As a nation we have to ask when in God's name we're going to stand up to the gun lobby. We have to act and don't tell me we can't have an impact on this carnage," he said.
The shooting as renewed calls for stricter gun laws in a country which saw a record 45,222 die due to gunshot wounds in 2020.
The National Rifle Association, America's powerful gun lobbying group, is set to hold a conference in Houston which will see former President Donald Trump, Governor Abbot, South Dakota Governor Kristi Noem, Senator Ted Cruz and other Republican leaders.
Ironically, attendees will not be allowed to bring guns to the conference.