A scaled-back version of President Donald Trump's travel is now in force, stripped of provisions that brought protests and chaos at airports worldwide in January yet still likely to generate a new round of court fights. The new rules, the product of months of legal wrangling, aren't so much an outright ban as a tightening of already-tough visa policies affecting citizens from six Muslim-majority countries.

Refugees are covered, too. Administration officials promised that implementation this time, which started at 8 p.m. EDT, would be orderly. Customs and Border Protection spokesman Dan Hetlage said his agency expected "business as usual at our ports of entry," with all valid visa holders still being able to travel. Still, immigration and refugee advocates are vowing to challenge the new requirements and the administration has struggled to explain how the rules will make the United States safer.

Under the temporary rules, citizens of Syria, Sudan, Somalia, Libya, Iran and Yemen who already have visas will be allowed into the United States. But people from those countries who want new visas will now have to prove a close family relationship or an existing relationship with an entity like a school or business in the U.S. It's unclear how significantly the new rules will affect travel. In most of the countries singled out, few people have the means for leisure travel. Those that do already face intensive screenings before being issued visas. Nevertheless, human rights groups girded for new legal battles.

The American Civil Liberties Union, one of the groups challenging the ban, called the new criteria "extremely restrictive," ''arbitrary" in their exclusions and designed to "disparage and condemn Muslims." The state of Hawaii filed an emergency motion Thursday asking a federal judge to clarify that the administration cannot enforce the ban against relatives — such as grandparents, aunts or uncles — not included in the State Department's definition of "bona fide" personal relationships.

Los Angeles City Attorney Mike Feuer met with customs officials and said he felt things would go smoothly. "For tonight, I'm anticipating few issues because, I think, there's better preparation," he told reporters at Los Angeles International Airport on Thursday night. "The federal government here, I think, has taken steps to avoid the havoc that occurred the last time."

Much of the confusion in January, when Trump's first ban took effect, resulted from travelers with previously approved visas being kept off flights or barred entry on arrival in the United States. Immigration officials were instructed Thursday not to block anyone with valid travel documents and otherwise eligible to visit the United States.