Prime Minister Nelson Oduber said his government was working closely with U.S. authorities to solve the case of 18-year-old Natalee Holloway, who dropped from sight more than a week ago.
"Nobody is above the law," Oduber said. "We are confident ... that we will solve this case."
Those detained Thursday were two brothers from Suriname and a 17-year-old Dutch student.
The 17-year-old met Holloway at a casino in her hotel, the Holiday Inn, two nights before she disappeared on May 30, Aruban Police Cmdr. Jahn van der Straaten told a news conference.
In Mountain Brook, Ala., Holloway's hometown, teens who went to Aruba with her were quoted as saying the Dutch teenager was at several places the group visited, including the restaurant-bar where the honors student was last seen.
Marcia Twitty, Holloway's aunt, said the Alabama students recognized the Dutch teenager from photos shown them by FBI agents. "They had seen him around during the trip. He was just a local guy in the bar and the casino where all the kids were just kind of hanging out," she said.
Attorney General Caren Janssen said the three men were arrested about 6 a.m. but refused to name them or say on what grounds they were being held. Authorities previously described them as students
two Surinamese brothers and the son of a Dutch justice official studying to be a judge.
"The three people have been arrested as suspects," chief government spokesman Ruben Trapenberg told The Associated Press.
Police also impounded a gray Honda; Holloway's friends reported last seeing her leave in a silver car.
Police identified the Surinamese brothers only as Satish and Deepak K. The Dutch detainee, a student at Aruba International School, left his home in the middle-class Montana neighborhood of Oranjestad on Thursday with his head covered in a blue-and-green striped towel.
Attorney general spokeswoman Vivian Van Der Biezan told a news conference the detainees were ages 17, 18 and 21.
The three had been detained last week but were released after questioning. Authorities had described them as witnesses "or persons of interest."
Under the Dutch judicial system, which Aruba follows as a protectorate of the Netherlands, people can be arrested on suspicion of a crime but held for up to 116 days without being formally charged. Authorities did not say what charges the three may face and the men will not be identified until they are charged.