The Department of Homeland Security in the US has issued a national terrorism advisory, warning of a heightened threat following the US election.
It said there was no information on a specific or credible plot.
But it said “individuals frustrated with the exercise of governmental authority and the presidential transition” could pose a threat.
An attack on the US Capitol by Trump supporters on 6 January has led to scores of arrests.
Earlier that day, as Congress was meeting to confirm Joe Biden’s election victory, the incumbent President Donald Trump had addressed thousands of his supporters outside the White House and repeated unfounded claims that the election was stolen from him.
He told them: “If you don’t fight like hell you’re not going to have a country any more.”
The crowd then made its way to the Capitol, overwhelming security and storming the building.
Mr Trump was impeached by the House of Representatives for incitement and is awaiting trial in the Senate.
The advisory issued on Wednesday said that the department believed a heightened threat would persist in “the weeks following the successful presidential inauguration”.
“Information suggests that some ideologically-motivated violent extremists with objections to the exercise of governmental authority and the presidential transition, as well as other perceived grievances fuelled by false narratives, could continue to mobilise to incite or commit violence,” it said.
BBC