WASHINGTON: U.S. House of Representatives Speaker Nancy Pelosi on Thursday created a new House committee to investigate the Jan. 6 attack on the U.S. Capitol, after Senate Republicans in May blocked an independent commission to probe the assault.

Some 500 people have now been arrested in the sweeping federal investigation into the violence, the Justice Department said on Thursday.

Speaking at a news conference, Pelosi, a Democrat, declined to spell out a timeline for the panel to investigate, saying it will be "as long as it takes". She gave no details of the make-up of the panel, but made clear both parties would be expected to name members, saying she hoped that House Republican Leader Kevin McCarthy will appoint "responsible people" to the panel.

Pelosi said it would have been preferable to have an outside commission, and that she had not totally given up on that idea. The House passed legislation to set up an independent bipartisan commission, but Senate Republicans blocked it, saying existing committee probes as well as prosecutors' investigations made it unnecessary.

"We see this as complementary, not instead of, and hopeful that there could be a commission at some point," Pelosi said.

In an assault that stunned America, hundreds of supporters of then-President Donald Trump stormed the Capitol on Jan. 6 in a failed attempt to stop Congress from certifying Democrat Joe Biden's presidential election victory. The violence left five dead, including a Capitol Police officer.

Trump has repeatedly falsely alleged that his electoral defeat was due to voter fraud, a claim dismissed by multiple courts, state election officials and his own administration's review.

"The Capitol of the United States has always been a glorious beacon of democracy for the American people and the world," Pelosi said.