"I got the blood and put it all on me," Miah Cerrillo,11, tells tearful lawmakers of Robb Elementary School massacre that left 19 of her classmates and two teachers dead, sparking widespread anger and calls for stricter gun laws.

"He... told my teacher 'good night' and then shot her in the head," Miah Cerrillo said in a brief but gut-wrenching pre-recorded interview. (AP)

An 11-year-old girl has told horrified lawmakers of smearing herself in her murdered classmate's blood to play dead during last month's mass shooting at a Texas elementary school, part of a series of gun massacres that have convulsed the United States.

Miah Cerrillo, a fourth-grader at Robb Elementary School in Uvalde, Texas, on Wednesday, recounted to a House of Representatives committee the moments when 19 of her fellow students and two teachers were killed by a teen gunman last month.

"He ... told my teacher 'good night' and then shot her in the head," Miah said in a brief but gut-wrenching pre-recorded interview.

"And then he shot some of my classmates and the whiteboard," she said, adding, "He shot my friend that was next to me ... and I thought he was going to come back to the room. I got the blood and put it all on me."

Miah recalled how she kept completely silent, before grabbing her dead teacher's cell phone when the moment came and dialing 911.

Police in Uvalde have come under intense scrutiny after it emerged that more than a dozen officers waited outside the door of Miah's class and did nothing as the children lay dead or dying.

Miah was asked what she wanted to see happen in the wake of the attack.

"To have security," she said, confirming that she feared a mass shooter could target her school again.

"I don't want it to happen again," she said.

READ MORE: US accounted for 73 percent of global mass shootings

'We demand action'

Miah – whose account of the shootings left some lawmakers in tears or wide-eyed in disbelief – is having nightmares and still healing from bullet fragments in her back, according to her father Miguel Cerrillo.

"She's not the same little girl I used to play with," he told the committee.

Her testimony came with Congress facing mounting pressure to respond to spiralling gun violence – and particularly mass shootings – across the country.

Massacres at Miah's school and days earlier at a supermarket in Buffalo, New York have shocked the nation, reigniting urgent calls for gun safety reforms.

The House Oversight and Reform Committee also heard from the mother of Lexi Rubio, a Robb Elementary fourth-grader who was killed.

"We don't want you to think of Lexi as just a number. She was intelligent, compassionate and athletic," Kimberly Rubio said via a video link, wiping away tears as she sat next to her husband Felix.

"She was quiet, shy, unless she had a point to make. When she was right, as she often was, she stood her ground. She was firm, direct, voice unwavering. So today we stand for Lexi and as her voice, we demand action."

Gun regulation reform

A cross-party group of senators is working on a narrow collection of controls that could develop into their first serious attempt at gun regulation reform in decades.

But it does not include an assault weapons ban or universal background checks, meaning it will fall short of the expectations of President Joe Biden, progressive Democrats, and anti-gun violence activists.

On the other side of the Capitol, House Democrats passed a much broader package of proposals later on Wednesday that includes raising the purchasing age for semi-automatic rifles from 18 to 21.

READ MORE: New York brings new curbs on guns as mass shootings plague US

Source: AFP