Washington (CNN) -- Supreme Court Justice Stephen Breyer was robbed last week by an intruder armed with a machete while Breyer was vacationing on the Caribbean island of Nevis, court officials said Monday.
Breyer, his wife and two other guests were in the justice's vacation home at the time, but officials said no one was hurt in the incident.
The male assailant took $1,000 in cash and fled the scene, according to court spokeswoman Kathy Arberg. The robbery was reported to local authorities shortly after it happened last Thursday night, and local media said no arrests had been made as of Monday.
A law enforcement official said the evidence so far indicates the incident was "a crime of opportunity," and that police have seen nothing so far to indicate Breyer was targeted for robbery.
The U.S. Marshals Service provides protection for members of the high court when they are traveling, and agency spokesman Jeff Carter said Monday that the marshals service "is aware of the incident involving Justice Breyer on the Caribbean island of Nevis and is assisting the Supreme Court Police and local law enforcement authorities with the investigation as needed." He did not elaborate.
FBI spokesman Paul Bresson said, "We are assisting the local police with their investigation."
Meanwhile, police on the island were "actively searching for a known person of interest," Commissioner C.G. Walwyn of the Royal St. Christopher and Nevis Police Force said Monday. "Our American-trained crime scene investigators and the members of our Criminal Investigators (unit) are working closely with the FBI on this case," he added.
Breyer had no comment on the matter, and the court would not say if he had returned to the United States. The high court is in recess this week, but the justices have scheduled a closed-door meeting Friday to go over pending court business, and they resume public sessions next week.
Nevis is part of the West Indies chain known as the Leeward Islands, located about 350 miles southeast of Puerto Rico.
The court does not talk publicly about specific security arrangements for the justices, either when they are at home or on their frequent travels. Justice Ruth Bader Ginsburg traveled to Egypt and Tunisia last month as part of an outreach program sponsored by the State Department, which provided her security in the volatile region.
Attacks on members of the federal judiciary are not new. Then-Justice David Souter was assaulted by a group of young males in 2004 while jogging alone in the evening near his Washington home. Souter suffered some minor bruises and was briefly treated then released from a local hospital.
Justice Byron White was attacked in July 1982 while giving a speech in Utah. That incident led to regular protection by U.S. marshals for members of the court when they travel.
The 73-year-old Breyer was nominated to the high court in 1994, and is known as one of the most active and engaging members of the court. His wife is Dr. Joanna Breyer, a renowned pediatric psychologist.
CNN's Nigel Walwyn and Carol Cratty contributed to this report.