The House Intelligence Committee formally opened a review into the Jan. 6 riots at the U.S. Capitol on Saturday and requested information from key federal law enforcement agencies to investigated whether "systemic failures" took place in protecting the Capitol and lawmakers.

In a letter addressed to FBI Director Chris Wray, director of national intelligence John Ratcliffe and other top intelligence officials, the committee asked agencies to "produce relevant documents, and schedule briefings, regarding specific intelligence matters associated with the insurrection and threats to the U.S. presidential inauguration."

The Committee says it plans to investigate whether federal law enforcement knew about the attacks before they happened.

"The Committees plan to review what the Intelligence Community and federal law enforcement knew about the threats of violence, whether that information was shared or not, and whether the threats had any nexus to foreign influence or misinformation efforts," the letter reads.

The letter was signed by several top Democrat House members including House Intelligence Committee Chair Adam Schiff, D-California and Committee on Homeland Security Chair Bennie Thompson, D-Mississippi, House Judiciary Chair Jerry Nadler, D-New York and Committee on Oversight and Reform Chair Carolyn Maloney, D-New York.

The riots, carried out by Trump supporters as Congress took steps to certify president-elect Joe Biden's win in the 2020 general election, left five people dead, including a Capitol police officer. In the days since nearly 50 people from more than 20 states have been charged with crimes relating to their alleged involvement in the riots.