Pentagon press secretary John Kirby confirmed that there was at least one other explosion near the airport, this at or near the Baron Hotel.

He said he can confirm that the explosion at Abbey Gate was a “result of a complex attack that resulted in a number of US & civilian casualties.”
Note: The term “casualties” can refer to those wounded or dead.
See Kirby’s tweet:
We can confirm that the explosion at the Abbey Gate was the result of a complex attack that resulted in a number of US & civilian casualties. We can also confirm at least one other explosion at or near the Baron Hotel, a short distance from Abbey Gate. We will continue to update.
— John Kirby (@PentagonPresSec) August 26, 2021