The Palm Beach Police Department says four people who came ashore the island this morning have been detained.

In an alert issued about 7:45 a.m., the department said it wanted to “inform the community of a maritime-based immigration incident that occurred early this morning” near 1200 N. Ocean Blvd.

A beached vessel was reported and “we located and detained four subjects, but there may be several more subjects outstanding,” police said.

Police spokesman Capt. Will Rothrock said three females and one male were taken into custody by the department and U.S. Border Patrol. Two of the females were taken to the hospital as a precaution, he said.

The 23-foot boat was “beached some time between midnight and 5 a.m.,” Rothrock said, and was found unoccupied about 5:30 a.m.

“Our intelligence unit is working the ongoing investigation with Border Patrol and Homeland Security,” Rothrock said.

The department is advising residents to call 561-838-5454 if they observe any suspicious persons or activity.

This is a breaking story please check back for updates.

Carol Rose is a journalist at the Palm Beach Daily News, part of the USA TODAY Florida Network. You can reach her at crose@pbdailynews.com. Help support our journalism. Subscribe today.

This article originally appeared on Palm Beach Daily News: Palm Beach Police detain four people after beached vessel found