President Donald Trump's immigration order sowed more chaos and outrage across the country on Sunday, with travelers detained at airports, panicked families searching for relatives and protesters registering opposition to the sweeping measure that was blocked by several federal courts.

Attorneys struggled to determine how many people were affected by the rules, which Trump said on Saturday were "working out very nicely." 

But critics described widespread confusion, with travelers being held in legal limbo because of ill-defined procedures.

Some lawyers manned tables at New York's Kennedy Airport to offer help to families with detained relatives.

"We just simply don't know how many people there are and where they are," said Lee Gelernt, deputy director of the American Civil Liberties Union's Immigrants' Rights Project.

Advocates for travelers say they did not have clear picture about what's happening and that the chaos is likely to continue. The executive director of National Immigration Law Center, Marielena Hincapie, said "this is just the beginning." 

"We're really in a crisis mode, a constitutional crisis mode in our country, and we're going to need everyone," she said. "This is definitely one of those all-hands-on-deck moments." 

Protests were planned or underway today, including one in suburban Chicago organized by Jewish groups to show support for Muslims, as well as at Dulles International Airport in Washington, DC, and Detroit Metropolitan Airport.

A federal judge in New York issued an order yesterday temporarily blocking the government from deporting people with valid visas who arrived after Trump's travel ban took effect.

But confusion remained about who could stay and who will be kept out of the country in the coming weeks. Federal courts in Virginia, Massachusetts and Washington state took similar action.

Michigan's civil rights chief, Agustin Arbulu, condemned Trump's order, saying he hoped the federal court ruling would led him to narrow its scope.

"During this time of uncertainty and confusion, we urge everyone to act with restraint and not in ways that foster fear and division," Arbulu said.

Criticism also continued abroad.

The European Union's foreign policy chief, EU High Representative Federica Mogherini, lashed out at Trump today, insisting that instead of building walls, the continent will "celebrate" every wall which is torn down and "every new bridge that is built up." 

Among those caught in limbo: Iraqis who had been promised a life in America because of their service to the US military, frail and elderly travelers from Iran and Yemen, and longtime US residents traveling abroad who don't know if they will be allowed to return home.