Washington Gov. Jay Inslee (D) slammed the Customs and Border Protection agency on Monday for allegedly detaining and questioning Iranian-Americans at the Canada-U.S. border in Blaine, Washington, which he attributed to the Trump administration’s “never-ending vilification” of immigrants.

“What Americans endured over the weekend in Blaine is unacceptable,” Inslee said in a statement. “This will not stand in Washington state, and we will continue to push for answers to ensure that it does not happen again.”

The governor asserted that the Trump administration, which has denied the allegations, could not be trusted to be forthright about the issue.

“Customs and Border Protection denials of these reports are simply not credible,” he said. “There are multiple firsthand accounts of CBP agents seizing people’s passports while they waited for up to 12 hours for re-entry into the United States.”

On Sunday, CBP spokesperson Michael Friel had said that the allegations were “false,” as was the Council on American-Islamic Relations’ report that the Department of Homeland Security had ordered CBP to detain those of Iranian descent, including U.S. citizens.

Immigration officials allegedly began the detentions after President Donald Trump dramatically escalated tensions with Tehran by having top Iranian general Qasem Soleimani assassinated via drone strike on Friday.