PHOENIX - The A and D security checkpoints in Terminal 4 at Phoenix Sky Harbor were closed Wednesday morning after a suspicious item passed through one of the checkpoints.

Police said officials were performing "additional screening" of the item. The area around the checkpoints was cleared as a precaution.

The Southwest and American ticket counters were also closed.

Aerial footage showed passengers boarding buses on the tarmac.

Airport officials said flight delays are expected and passengers should check their flight status.

Officials have yet to release information regarding the suspicious item.

This story will be updated.