SILVER SPRING, Md. ― Many of the Muslims gathered at a community center here on Sunday to learn more about President Donald Trump’s recent executive order won’t necessarily be targeted by it directly, but they were frightened anyway.

The reason for that fear: Trump has only been president for nine days, and he already made a drastic policy change that disproportionately affects Muslims, whom he once vowed to bar from entering the country entirely. The roughly 150 people at Silver Spring’s Muslim Community Center are worried about what Trump will do next.

“Some of the things that happen, they lead to bigger things,” said Samina Ali, 65, who is originally from Pakistan and has been a U.S. citizen for 40 years. “I was reading about the Holocaust, and this is how it all started: small incidents and they got bigger and bigger and bigger. ... I think that’s the extreme ― those were different days and these are different days ― but of course it does concern you.”

Her daughter, 45-year-old Sarah Shakir, added that she knows the current executive order doesn’t apply to native-born American citizens like herself or naturalized ones like her mother, but the next orders might.

“I feel like that could change any minute, and that’s what’s really frightening for me,” Shakir said.

Trump signed an executive order on Friday that halts all refugee resettlement for 120 days, bars Syrian refugees indefinitely and places a 90-day ban on entry for nationals of seven countries: Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen.

There was a striking lack of clarity about the order, which the White House did not release until 2 and 1/2 hours after Trump signed it, leaving people to speculate and fret over what was inside. Some things are still unclear, such as whether green card-holders will continue to be part of the ban ― White House officials contradicted themselves on this point, before finally announcing later Sunday that green card holders should be admitted. It’s also not clear how a court order that temporarily blocked parts of the ban will play out in the coming days.

That lack of clarity was part of why people gathered at the Muslim Community Center, where children went to Sunday school or played while their parents asked experts what to make of what had happened.

The event’s speakers, Abed Ayoub of the Arab American Anti-Discrimination Committee and law professor Khaled Beydoun, didn’t sugarcoat things: They predicted that although there have been positive signs in the courts and in public support, Trump has more up his sleeves.

“This ban is the first of many Islamophobic policies still to come,” Beydoun said.

Many people asked for specifics on the ban related to people with a green card who are not from one of the seven countries targeted in the order: Should doctors from other Arab countries avoid going on a trip to provide pro bono medical care? Should a legal permanent resident from Pakistan come back to the U.S. immediately?

Beydoun and Ayoub said they think more countries could be added to the list. In other words, someone from Pakistan might not be affected now, but could be at any moment. They advised the group to act accordingly.

“If you assume that your country is going to be added, and I think that’s a majority of all Arab or Muslim nations, then it’s probably best to stay put until we straighten this out and figure out what’s going on,” Ayoub said of people already in the U.S.

He said that people should also keep an eye out for a travel ban that prevents entry into the U.S. for people who recently visited one of the seven countries, or potentially others as well. The current order applies solely to nationality, so if a British citizen, for example, took a trip to Syria, he or she would still be able to come to the U.S.

Then there were concerns beyond the order itself, such as whether Trump will create a Muslim registry and whether, if he does, people should agree to join it. The speakers said that a registry is likely but that it probably wouldn’t involve U.S. citizens signing up ― more likely, it would be along the lines of President George W. Bush’s National Security Entry-Exit Registration System, or NSEERs, that tracked non-citizens when they entered the country.

That doesn’t mean a U.S. citizen would have nothing to fear in a registry ― Beydoun said he thinks surveillance could allow the government to collect a considerable amount of information about American Muslims.

Attendees of the meeting asked how they should handle airport screening, already a problem for many that has the potential to now get even worse. The experts advised the group to know their rights, answer questions broadly and make sure a trusted individual or a lawyer knows their flight information, just in case they are detained upon arrival.

Travel was a concern for Saira Ahmed, 40, who said she and her husband will wait and see whether they should visit their parents in Pakistan. They are both U.S. citizens, as are their three boys. Pakistan isn’t on the list of countries in Trump’s executive order, but they want to see how things play out before making plans.

“Even though we’re citizens, you just don’t know what’s going to happen,” Ahmed said. “Just because you’re a Muslim, are you going to be labeled? Is this our version of the Holocaust that’s about to start; are we about to be branded?”