Two individuals flying on a Chicago-Amsterdam United Airlines flights have been arrested on Tuesday in the Netherland on charges of “preparation of a terrorist attack”, a media report in Washington said.

The two individuals identified as Ahmed Mohamed Nasser al Soofi of Detroit and Hezem al Murisi were allowed to board the flight from Chicago on Sunday night that one of them had a suspicious activities, law enforcement authorities were quoted as saying by the US media.

According to ABC News, which was the first to report the incident, two US officials said the two appeared to be travelling with what were termed “mock bombs” in their luggage.

“This was almost certainly a dry run, a test,” one senior law enforcement official was quoted as saying.

The two men did not had prohibited items on them, a law enforcement official told the Fox News, saying that although knives were found in their checked luggage, such checked items aren’t prohibited.

The individuals also were not on the no-fly list, nor were there any active warrants for their arrest, the news channel said.

“Suspicious items were located in checked luggage associated with two passengers on United Flight 908 from Chicago O’Hare to Amsterdam,” the Transportation Safety Administration said. “The items were not deemed to be dangerous in and of themselves,” it said.