The Washington Post reported on Monday that concerns are mounting within President Donald Trump’s administration and the Pentagon that the conflict with Iran could spiral out of control.

Citing unnamed sources familiar with the matter, the newspaper said the mood inside the U.S. military establishment is marked by a degree of unease amid the current escalation.

According to the report, there is “growing concern” within parts of the Pentagon and some circles of the Trump administration that the confrontation with Iran could expand in ways that would be difficult to contain.

There was no immediate comment from the White House or the Department of Defense on the report.