A satanic disciple had stowed away on a flight to Florida, as one passenger saw it, and something had to be done.

Less than a minute after an American Airlines flight took off from Savannah, Ga., for Miami on Monday night, a passenger began yelling and shaking. Flight attendants initially thought he was having a seizure.

But it turned out he was struggling because he believed a demonic spirit had invaded the cabin — and, at some point during the flight, began swallowing rosary beads to ward that spirit off.

As attendants approached the man, Delange Augustin, 31, he kicked one of them in the chest so hard that the attendant tumbled across the aisle and into a window on the other side of the plane, according to an arrest affidavit.

That’s when the cabin crew realized that Mr. Augustin, who was traveling with his sister, was not having a medical emergency. “Augustin’s choices appeared purposeful, though difficult to describe,” Savannah Solomon, a special agent with the F.B.I., wrote in the affidavit filed in the United States District Court in Chatham County.

The pilots turned the plane around when they heard the commotion and landed it safely in Savannah. But that was not the end of the episode.

Disembarkation from the jet spiraled into chaos when Mr. Augustin stormed to the front of the plane and threw several wild punches at a flight attendant before the door had been opened, the affidavit said. Several passengers helped to wrestle him and his sister to the ground.

Then the authorities learned that Mr. Augustin had swallowed the rosary beads. So he was taken to a hospital, where he was evaluated and discharged to a county detention center. His medical condition was not immediately clear as of Tuesday night.

In the detention center, Mr. Augustin’s sister told the authorities that they had been traveling to Haiti to “flee religious attacks of a spiritual nature,” according to the affidavit.

Mr. Augustin had told his sister “to close her eyes and pray because Satan’s disciple(s) had followed them onto the plane and the legion did not want the Augustins to make it to Haiti,” it said. He swallowed the rosary beads “because they are a weapon of strength in the spiritual warfare,” Mr. Augustin’s sister told Ms. Solomon.

Only about eight passengers were on the plane, the affidavit said. No one was seriously injured.

“We appreciate the professionalism of the entire crew and thank our passengers for their understanding,” American Airlines said in a statement on Tuesday night.

Envoy Air, which operated the flight, did not immediately respond to an email seeking comment.

Mr. Augustin was booked into jail on a misdemeanor battery charge, a misdemeanor obstruction of law enforcement charge and a felony count of criminal property damage, according to the jail’s records. Ms. Solomon said in her affidavit that there was also probable cause to arrest him for interfering with the flight crew.

No lawyer for Mr. Augustin was listed in court records. His place of residence was not immediately clear.

Sheelagh McNeill contributed research.