Updated

THE HAGUE, Netherlands (AP) — Two Yemeni men arrested on arrival from the United States on suspicion they may have been conducting a dry run for an airline terror attack were released without charge Wednesday after investigations turned up no evidence to link them to a terror plot, Dutch prosecutors said.

The national prosecutor's office said in a statement on its website that because of the lack of evidence "there is no reason to hold the men any longer."

Ahmed Mohamed Nasser al-Soofi and Hezam al-Murisi were arrested by airport police Monday in Amsterdam on a United Airlines flight from Chicago following a request from U.S. law enforcement officials.

The whereabouts of the two men following their release was not immediately known. Their lawyers could not immediately be reached for comment.

Prosecutors said an initial test by U.S. authorities on an item of luggage belonging to one of the men "showed the possible presence of a trace of explosives."

However "more accurate" later tests did not reveal any signs of explosive material, the prosecutors said.

"Investigations in the U.S. and the Netherlands have shown that there is no longer any indication of any possible involvement of the men in any crime," the prosecution statement said.

Their arrests came just days before the ninth anniversary of the Sept. 11, 2001, terror attacks in the United States.

Al-Soofi's Dutch lawyer Wouter Hendrickx told The Associated Press before news of the release broke that al-Soofi insists he is innocent.

"He says 'I have no connections to terrorist activities whatsoever,'" Hendrickx said.

Hendrickx said al-Soofi was on his way to Yemen to visit his family when he was detained.

Al-Soofi and al-Murisi missed flights to Washington Dulles International Airport from Chicago, and United Airlines then booked them on the same flight to Amsterdam, a U.S. government official said. The men were sitting near each other on the flight, but not together.

Al-Soofi also raised suspicions in the United States on Sunday because he was carrying $7,000 in cash. An inspection of his checked luggage uncovered a cell phone taped to a small bottle, multiple cell phones and watches taped together, and a knife and box cutter, according to a U.S. official who had been briefed on the investigation.

None of the checked items violated U.S. security rules, so authorities allowed al-Soofi to fly. But his bags later were transferred to another flight and were not on the flight to Amsterdam, Dutch prosecutors said.

Al-Soofi and al-Murisi changed their travel plans at the last minute and took a direct flight to Amsterdam, raising suspicion among U.S. officials.