Armed forces loyal to Moammar Gadhafi captured three Dutch marines and their helicopter during a botched evacuation mission near a stronghold of the Libyan leader, the Defense Ministry said Thursday.

Libyan authorities are still holding the marines five days after they were seized Sunday by armed men after landing near Sirte in a Lynx helicopter from the navy ship HMS Tromp. The ship was anchored off the Libyan coast to help evacuations from the conflict-torn country, spokesman Otte Beeksma told The Associated Press.

Two Europeans, one Dutch and one whose nationality was not released, were also captured. They were handed over unharmed to the Dutch embassy in Tripoli early Thursday and have left Libya, the ministry said.

Prime Minister Mark Rutte said his government authorized the mission.

Dutch officials are in “intensive negotiations” with Gadhafi’s government to secure the marines’ release, he said.

“We have also been in contact with the crewmen involved,” Beeksma said. “They are doing well under the circumstances and we hope they will be released as quickly as possible.”

Defense Minister Hans Hillen welcomed the news that the two Europeans were safe and had left Libya. “Everything is being done to also get the crew safely out of the country as soon as possible,” he said in a statement.

Asked if the Dutch government considered the marines hostages, Beeksma said, “they are being held by Libyan authorities.”

Rutte said news of the men’s capture was kept quiet to assist talks on their release. Dutch daily De Telegraaf first reported their capture in its Thursday edition.

“These are situations that benefit from total secrecy because then you can carry out discussions in peace to ensure these people get home safely,” Rutte told national broadcaster NOS.

“It is terrible for the crew of the Lynx helicopter,” he said. “Everything is being done to make sure the crew gets home.”

The marines’ identities were not released.

On Wednesday, Gadhafi warned the U.S. and other Western powers not to intervene in the chaos enveloping his country. He vowed to turn Libya into “another Vietnam,” and said any foreign troops coming into his country “will be entering hell and they will drown in blood.”

In a speech to chanting and clapping supporters in Tripoli, Gadhafi vowed to fight on “until the last man and woman. We will defend Libya from the north to the south.”

Military expert Christ Klep from the Clingendael think tank said the marines’ capture was a coup for Gadhafi, who could possibly use them as bargaining chips in negotiations with the West.

“Yes, that is a very serious consideration. They are in military uniform,” he said. “It’s an easy situation for Gadhafi to exploit.”

Gadhafi’s crackdown has been the harshest of the wave of anti-government protests sweeping across parts of the Middle East and North Africa. His forces are regrouping in an attempt to regain territories now controlled by opponents of his regime.

The prosecutor of the International Criminal Court, Luis Moreno-Ocampo, said Thursday he will investigate Gadhafi and his inner circle for possible crimes against humanity for attacking peaceful demonstrators.