Spike in death threats against Ilan Omar following Trump 9/11 tweet

Muslim American congresswoman Ilhan Omar has said she has received a rising number of death threats following President Donald Trump's repeated tweets against her, which included video footage of September 11 attacks and accusations that she downplayed their horror.

"Since the president's tweet Friday evening, I have experienced an increase in direct threats on my life - many directly referencing or replying to the president's video," Omar said in a statement issued on Sunday night.

Omar thanked the Capitol police, the FBI, the House sergeant at arms and the speaker of the House, confirming that they were all aware of the threats she received.

"Violent rhetoric and all forms of hate speech have no place in our society, much less from our country’s Commander in Chief," the 37-year-old Somali-American said in the statement.

"We are all Americans. This is endangering lives. It has to stop," Omar added.

The White House intensified its attacks against Omar on Sunday, with its press secretary Sarah Sanders insisting that Omar - one of the first Muslim women in Congress and the first to wear a hijab in the House chamber - was in the wrong.

"I find her comments to be absolutely disgraceful and unbefitting of a member of Congress," said Sanders, who thought that "it's a good thing the president is calling her out".

Sanders disregarded Democrats concern that the US president was inciting violence against Omar, who had previously received death threats, and against other Muslim-Americans.

"The president is wishing no ill will and certainly not violence toward anyone," said Sanders. "But the president is absolutely and should be calling out the congresswoman," Sanders continued.

Omar has been at the center of an escalating row after a video emerged of her characterizing the deadliest attack on US soil as "some people did something".

On Friday, US president tweeted a video that juxtaposed the snippet, which Omar's fellow Democrats say was taken out of context, with images of the hijacked planes used in the 9/11 terror attacks.

The clip, which was viewed by millions, ends with the words: "SEPTEMBER 11 2001 WE REMEMBER."

Prominent Democrats including Beto O'Rourke, Kamala Harris and Omar's fellow first-time Congresswoman Alexandria Ocasio-Cortez rushed to defend Omar, accusing Trump and other Republicans of deliberately de-contextualizing her remarks and exposing her life to threats.

Former representative Beto O'Rourke and New York congresswoman Alexandria Ocasio-Cortez said Trump's attacks amounted to an "incitement to violence".