The Supreme Court ruled unanimously Wednesday that a federal law that allows torture victims to sue their overseas assailants does not permit suits against corporations or political groups such as the Palestine Liberation Organization.

The justices said the Torture Victim Protection Act of 1991 authorized lawsuits only against individuals responsible for torture and killing.

“The text of the TVPA convinces us that Congress did not extend liability to organizations, sovereign or not,” Justice Sonia Sotomayor wrote for the united court.

“There are no doubt valid arguments for such an extension. But Congress has seen fit to proceed in more modest steps in the act, and it is not the province of this branch to do otherwise.”

The legislation authorizes lawsuits in U.S. courts against “an individual” who “under actual or apparent authority, or color of law, of any foreign nation” tortures a person or takes part in an “extrajudicial” killing.

The case before the court involves a lawsuit filed by the family of Palestinian American Azzam Rahim. Rahim immigrated to the United States in the 1970s and returned to the West Bank in 1995. His family alleged that he was arrested by Palestinian Authority intelligence officers and imprisoned, tortured and eventually killed in a Jericho prison.

Rahim’s survivors filed suit in 2005 against the PLO and the Palestinian Authority. A district judge and the U.S. Court of Appeals for the D.C. Circuit dismissed the case, saying only people can be sued under the language of the TVPA. But other lower courts have said that such suits could proceed against corporations and other entities.

Human rights organizations had argued that the law was “toothless” if suits were limited to individuals rather than entities that might have controlled the torture or killings.

Sotomayor acknowledged that that might be true but wrote that “Congress appeared well aware of the limited nature of the cause of action it established in the act.”

Although the law does not define the word “individual,” she noted, Congress seemed to go out of its way to make sure that the term referred only to people.

The legislation’s text “evinces a clear intent not to subject non-sovereign organizations to liability,” she wrote.

The case is part of an effort by human rights groups to use U.S. courts to avenge torture and killings overseas. Foreign governments are largely protected from suits in the United States because of the Foreign Sovereign Immunities Act. But dozens of suits have been filed against multinational corporations under the TVPA and a 1789 act, the Alien Tort Statute.

The Supreme Court heard an argument this year about whether the ATS allows corporations to be held liable for human rights abuses committed abroad in which they might have been complicit. But the justices put off a decision to look at a broader question next term: whether anyone can be sued under the statute for violations of international law that occur in other countries.

The ATS case is Kiobel v. Royal Dutch Petroleum Co. The case decided Wednesday is Mohamad v. Palestinian Authority .