MIAMI — President Donald Trump’s new ban on travel to the U.S. by citizens from a dozen countries took effect Monday with relative calm, as some travelers with valid visas reported extra scrutiny at American airports before being allowed entry.

The ban targeting mainly African and Middle Eastern countries kicked in amid rising tension over the president’s escalating campaign of immigration enforcement. But it arrived with no immediate signs of the chaos that unfolded at airports across the U.S. during Trump’s first travel ban in 2017.

The new proclamation that Trump signed last week applies to citizens of Afghanistan, Myanmar, Chad, the Republic of Congo, Equatorial Guinea, Eritrea, Haiti, Iran, Libya, Somalia, Sudan and Yemen. It also imposes heightened restrictions on people from Burundi, Cuba, Laos, Sierra Leone, Togo, Turkmenistan and Venezuela who are outside the U.S. and don’t hold a valid visa. The new ban does not revoke visas previously issued to people from countries on the list, according to guidance issued Friday.

— The Associated Press