Health experts double down on their advice for slowing the spread of the coronavirus.

And what else you need to know today.

The Tunisian capital beckons with white-sand beaches, the medina, cafe districts and Roman ruins that speak to its place in history. Luckily, there are ways to capture its spirit at home.

Why do some mass gatherings turn violent? Experts in crowd behavior say there’s still much to learn.

An impeachment charge against Trump.

The Trump administration did not wait to put in place legal protections for aid workers, a lapse that officials said could halt shipments of food, medicine, gasoline and other assistance.

In announcing the move, Secretary of State Mike Pompeo cited Cuba’s hosting of American fugitives and Colombian rebels and its support for Venezuela’s authoritarian leader.

Madrid was blanketed with the heaviest snowfall in five decades after Storm Filomena covered the city and surrounding areas in Spain with more than a foot and a half of snow.

The Treasury Department accused seven Ukrainians of working with a Russian agent “to spread misleading and unsubstantiated allegations” about President-elect Joseph R. Biden Jr.

Trump’s second impeachment.