WASHINGTON — The US Department of Homeland Security issued a new warning over domestic terrorism Friday, saying violent extremists could exploit the easing of Covid-19 restrictions to conduct attacks.

In an update of a January alert following the attack on the US Congress by supporters of then-president Donald Trump, DHS said the country faces “increasingly complex and volatile” threats from anti-government and racially-motivated extremists, often stirred up by online influence from abroad.

“We are advising the public to be vigilant about ongoing threats to the United States, including those posed by domestic terrorism, grievance-based violence, and those inspired or influenced by foreign terrorists and other malign foreign influences,” said Homeland Security Secretary Alejandro Mayorkas.

The official advisory came as the country removed many coronavirus restrictions, and after Washington eased security measures taken following the January 6 attack on the Capitol.

Those measures saw thousands of National Guard troops deployed on the capital’s streets and tall fencing around key buildings.

“Violent extremists may seek to exploit the easing of COVID-19-related restrictions across the United States to conduct attacks against a broader range of targets after previous public capacity limits reduced opportunities for lethal attacks,” the advisory said.

It said that false narratives and conspiracy theories continue to flourish online.

Some “called for violence against elected officials, political representatives, government facilities, law enforcement, religious or commercial facilities, and perceived ideologically-opposed individuals,” it said.

The advisory also said that Russia, China and Iran government-linked media outlets continue to stir up and amplify grievances and conspiracy theories on social media “to sow discord.”

For example, it said, they have promoted false stories about coronavirus vaccines and encouraged violence against people of Asian descent.

The advisory also warned of continuing efforts by Islamist extremist groups Islamic State and Al-Qaeda to inspire home-grown extremists to carry out attacks.