A spokesman for the Taliban told Britain’s Channel 4 News on Thursday that the insurgent group is scouring classified American military documents posted online by the group WikiLeaks for information to help them find and “punish” Afghan informers.

Speaking by telephone from an undisclosed location, Zabihullah Mujahid, who frequently contacts news organizations, including The Times on behalf of the Taliban, said, “We are studying the report.” He added:

We knew about the spies and people who collaborate with U.S. forces. We will investigate through our own secret service whether the people mentioned are really spies working for the U.S. If they are U.S. spies, then we know how to punish them.

Steve Coll, an expert on the region and a former senior editor of The Washington Post, said in a New Yorker podcast on Thursday, “my reading of the disclosure of these informants in the context of Taliban-menaced southern Afghanistan is that people named in those documents have a reasonable belief that they are going to get killed, or — actually the way it works with the Taliban is, if they can’t find you, they’ll take your brother instead.”

Channel 4 News also reported that the spokesman said that the Taliban “had come to know of the leaked secret documents through media reports.”

As my colleagues Eric Schmitt and Charlie Savage reported on Wednesday:

A search by The New York Times through a sampling of the documents released by the organization WikiLeaks found reports that gave the names or other identifying features of dozens of Afghan informants, potential defectors and others who were cooperating with American and NATO troops. The Times and two other publications given access to the documents — the British newspaper The Guardian and the German magazine Der Spiegel — posted online only selected examples from documents that had been redacted to eliminate names and other information that could be used to identify people at risk. The news organizations did this to avoid jeopardizing the lives of informants. The founder of WikiLeaks, Julian Assange, has said that the organization withheld 15,000 of the approximately 92,000 documents in the archive that was released on Sunday to remove the names of informants in what he called a “harm minimization” process. But the 75,000 documents WikiLeaks put online provide information about possible informants, like their villages and in some cases their fathers’ names.

At a Pentagon news conference on Thursday, Secretary of Defense Robert Gates told reporters that “intelligence sources and methods” detailed in the documents “will become known to our adversaries,” now that they have been posted online. As Mr. Savage reported, the chairman of the Joint Chiefs of Staff, Adm. Mike Mullen, said at the same briefing:

Mr. Assange can say whatever he likes about the greater good he thinks he and his source are doing, but the truth is they might already have on their hands the blood of some young soldier or that of an Afghan family.

In a response read to CNN, Mr. Assange, who seemed confused about which Pentagon official had said what, attacked Mr. Gates for speaking about “hypothetical blood” while, he said, “The grounds of Iraq and Afghanistan are covered with real blood.” He added, “Secretary Gates has overseen the killings of thousands of children and adults in these two countries.”

In the New Yorker podcast, Mr. Coll also suggested that WikiLeaks apparently made documents naming Afghan informants available online without proper consideration.

“If you’re going to put somebody like that on the line, you better have a really compelling reason to do it,” he said. “I don’t see in this process that care was taken of intelligence was applied to those life and death questions.”

In an interview with NBC News on Wednesday, Mr. Assange said WikiLeaks was studying what he called “rumors” that the documents posted on its Web site include the names of informants. He also said that the organization had relied in part on the level of classification given to the reports by the American military and said, “If there are those names there, and they are at risk, this would be because of a misclassification by the U.S. military itself.”

Stephen Engelberg, the managing editor of ProPublica and a former national security correspondent for The Times, wrote on Friday that the Afghan war documents published by WikiLeaks, some apparently without thorough review, signal a new era in advocacy and journalism on the Web: