The online message board 8chan, linked to several recent mass shootings, plans to restrict parts of the website during a "state of emergency," the site's owner, Jim Watkins, told a U.S. House panel in a written statement.

"If 8chan comes back online, it will be done when 8chan develops additional tools to counter illegal content under United States law," Watkins said in the statement released by his lawyer.

"If 8chan returns, staff would implement a way to restrict certain parts of the website during a state of emergency, in which case any board in question would be put in a read-only mode until it would be deemed safe enough to enable posting again," it said.