SAN FRANCISCO — A panel of appeals court judges reviewing President Donald Trump’s travel ban hammered away Tuesday at the federal government’s arguments that the ban was motivated by concerns about terrorism, but also questioned an attorney who said it unconstitutionally targeted Muslims.

The hearing before the San Francisco-based 9th Circuit Court of Appeals judges was the greatest legal challenge yet to the ban, which temporarily suspended the nation’s refugee program and immigration from seven mostly Muslim countries that have raised terrorism concerns.

Judge Michelle T. Friedland, who was appointed by President Barack Obama, asked whether the government has any evidence connecting the seven nations to terrorism.

August Flentje, arguing for the Justice Department, told the judges that the case was moving fast and the government had not yet included evidence to support the ban. Flentje cited a number of Somalis in the U.S. who, he said, had been connected to the al-Shabab terrorist group after judges asked for evidence.

Judge Richard Clifton, a George W. Bush nominee, asked an attorney representing Washington state and Minnesota, which are challenging the ban, what evidence he had that it was motivated by religion.

“I have trouble understanding why we’re supposed to infer religious animus when in fact the vast majority of Muslims would not be affected.”

He said only 15 percent of the world’s Muslims were affected, according to his calculations, and said the “concern for terrorism from those connected to radical Islamic sects is hard to deny.”

Noah Purcell, Washington state’s solicitor general, cited public statements by Trump calling for a ban on the entry of Muslims to the U.S. He said the states did not have to show every Muslim is harmed, only that the ban was motivated by religious discrimination.