SAN NICOLAS, Aruba -- At least 70 people attended a prayer vigil Sunday night in Aruba for missing Alabama teenager Natalee Holloway.

One speaker at the 10-minute ceremony said the so-far unsuccessful search for Holloway is a trying time "for the world as a whole."

Holloway had been visiting the island last week with classmates to celebrate their high school graduation when she disappeared.

A reward of $50,00 is being offered for information leading to her rescue.

Police in Aruba said Sunday that a blood-soaked mattress found on a beach in eastern Aruba over the weekend was not related to the missing girl.

The two men being detained are security guards at the Allegra Hotel, which is near where Holloway was staying, Birmingham television station WVTM reported.

Aruba Attorney General Carin Jansen told reporters gathered at a press conference Sunday that while the arrest of two men was related to the case due to unspecified "tips," she declined to provide further details.

She would not say whether there was a connection between those two men and three others who had previously been questioned in connection with the Mountain Brook teen's disappearance.

Jansen answered most questions from reporters with a terse, "That is part of the investigation, and I can't discuss it."

Several additional details on the search for Holliway did come out during the press conference.

Jansen confirmed that law enforcement officials in Aruba had asked for help from an FBI diving team. She also told reporters that while police had not confiscated clothing or other items that would directly link the two arrested men to Holloway, they had seized other "items of interest to the case."

She also said that the two men arrested were considered "solid leads" in the case.

As for how long the investigation would continue, Jansen said that it would continue "as long as needed. It could be two weeks...three weeks. However long it takes for us to complete the picture."

Following a tip, police also searched the Allegra on Saturday. No sign of Holloway was found during the search, but a further investigation led to the arrest of the two men.

It is not yet clear what charges are being brought against the pair.

Holloway was on a five-day excursion with 124 seniors and several chaperones from Mountain Brook High School, near Birmingham. Holloway was last seen early May 30.

She did not show up for her return flight, and police found her passport in her hotel room with her packed bags.