The U.S. has seen increasing indications that Iran could be planning an attack against American forces or interests in the Middle East, according to a U.S. official.

The U.S. official, who spoke on condition of anonymity, acknowledged that reading Iran’s intentions was “difficult and at times unpredictable.”

But the indications are being taken seriously, the official said. The one-year anniversary of the U.S.’ killing of top Iranian general Qassem Soleimani is just days away…

This week, the U.S. flew B-52 bombers based at a Minot, North Dakota, Air Force base to the Middle East in a “deliberate appearance,” U.S. Central Command said, in the second such show of force this month.