Six Syrians and a Cuban who were detained in Panama after a flight crew reported suspicious behavior told authorities that three of them had approached the cockpit by mistake, police said Tuesday.

The men, who were traveling together on a Copa Airlines flight from Cuba, were also suspected of taking a knife that went missing after breakfast was served in the first-class cabin where they were sitting, Panama's National Police said in a news release.

Police said three of the men approached the cockpit door and tried to open it. They told investigators they confused it with the bathroom, the statement said. Panama's Judicial Police also said the men tried to get into the cockpit.

Earlier, Panamanian Civil Aviation Authority spokesman Victor de la Hoz had denied that the passengers tried to gain access to the cockpit, and said the Copa Airlines crew simply notified authorities on the ground that a knife was missing.

"This is not a hijacking," he said.

It was not immediately possible to reconcile the different stories.

The six were still under arrest at Panama's international airport Tuesday night.

Panama's National Police director, Rolando Mirones, said the suspects "did not commit any violent acts inside the airplane, but they raised suspicions," adding: "That is why we are investigating."

The plane landed safely shortly before noon.

Judicial Police Director Jose Ayu Prado said the Syrians, ages 17 to 30, were headed for Haiti and Jamaica after a layover in Panama.

The Cuban passenger was en route to Argentina, the aviation authority said in a statement.

Like many commercial airlines, Copa ordered cockpit doors locked on its jetliners after the Sept. 11, 2001, airplane attacks in the United States.