Excerpts from video posted on a social media Web site on Tuesday show a leader of al-Qaeda on the Arabian Peninsula claiming responsibility for the attack on Charlie Hebdo. The original video is 11 minutes long. (Reuters)

U.S. intelligence has concluded that a video by al-Qaeda’s affiliate in Yemen asserting responsibility for last week’s massacre at a Paris newspaper is genuine, but it has found no evidence so far to support the group’s declaration that it directly planned, ordered and funded the attack, Obama administration officials said.

Some officials and experts suggested that the video, released Wednesday by al-Qaeda in the Arabian Peninsula, was an attempt by the group to enhance its militant profile and steal the spotlight from the Islamic State as the two compete for attention, recruits and financing.

As U.S. and French intelligence agencies scramble for more information, U.S. officials emphasized that the fact that they have not yet found any direct communication between AQAP and the attackers in recent days, weeks or even years does not mean it doesn’t exist.

“The questions are legitimate,” a U.S. intelligence official said. “Was there some sort of call from AQAP, saying ISIL is eating our lunch and we need to do something?” ISIL and ISIS are acronyms for the Islamic State, an offshoot that is at odds with the main al-Qaeda organization and has declared a caliphate in Syria and Iraq.

“Or was it just that these guys took a long time” to carry out a plot hatched by AQAP in 2011, asked the official. That year, at least one of the Charlie Hebdo attackers — brothers Said and Chérif Kouachi — is known to have visited Yemen, had contact with AQAP and returned with cash, according to officials.

Even without evidence of a recent call or message, the intelligence official said, the Kouachi brothers were “clearly inspired” by AQAP. In addition to their travel to Yemen and declarations of AQAP fealty before they were killed by French security forces, there was a known “desire on behalf of AQAP to strike out against individuals that had insulted the prophet.” The targeted satirical weekly has for years published cartoons depicting the prophet Muhammad.

“It’s not inconceivable that these guys did come back” from Yemen to France, “had this plan for some time, and were just waiting for the right time to do it,” said the official, who was not authorized to speak publicly on the matter.

Rep. Adam B. Schiff (Calif.,) who as the ranking Democrat on the House Intelligence Committee has been briefed on the investigation, said, “It may very well be that they got a list of targets” in Yemen and were “encouraged to attack the magazine.”

“When they got back to France, they thought better of it for a while. That may account for the delay, rather than the strategic idea of a sleeper cell” waiting for AQAP activation nearly four years later, Schiff said.

In the 11-minute video, posted Wednesday online, an AQAP leader, Nasr al-Ansi, said his organization “chose the target, laid the plan, financed the operation.” He said that al-Qaeda’s overall chief, Ayman al-Zawahiri, ordered the attack.

Ansi, the Yemen affiliate’s main ideological guide, went on to praise the Kouachis as “heroes of Islam” and said that after they received their assignment, “they promised and fulfilled.”

A total of 17 people were killed over three days of bloodshed that ended with twin police raids Friday that killed the two brothers and another gunman, Amedy Coulibaly, who had taken hostages at a kosher grocery in Paris. France’s Justice Ministry said that at least 54 people have been detained as part of the terrorism investigation.

Ansi referred to Coulibali as a “brother” but did not claim credit for his actions. In a video released after his death, Coulibali said he was a follower of the Islamic State.

Apparently referring to marches against the attacks attended by millions in Western capitals last weekend, Ansi said: “Look how they have gathered, rallied and supported each other; strengthening their weaknesses and dressing their wounds. Those wounds have not healed and they won’t, be it in Paris, New York or Washington, or in London or Spain, or in Palestine the legend of glory and pride,” according to a translation from Arabic provided by the SITE Intelligence Group.

Asked for additional information about the video, an individual who has claimed to represent AQAP and who has previously provided statements and other information to The Washington Post said he would no longer do so because of the paper’s decision to publish the first post-attack cover of Charlie Hebdo, released this week.

“We just deal with those who refuse to publish,” he said in an encrypted communication on Wednesday.

Officials and experts differed on the meaning of several aspects of the video claim.

Some said the method of attack — men on foot with automatic rifles — did not fit with AQAP patterns. “I remain skeptical that this was an AQAP-directed strike,” said Brian Fishman, a fellow at the New America Foundation and the Combating Terrorism Center at West Point. “It certainly does not fit the tactical hallmark of AQAP, which is the very creative use of small explosives.” AQAP’s most notable past plots have been foiled attempts to blow up civilian airliners.

“My hypothesis is that when Said Kouachi visited Yemen, he was probably greeted warily by AQAP, which at that point was increasingly paranoid about potential infiltration by Western spies,” Fishman said. “So they train him a bit, direct him toward relatively soft targets . . . and then send him on his way.”

On the other hand, AQAP could be “falling back on an old strategy” after its failure for five years to “have a spectacular attack,” said Bruce Hoffman, director of Georgetown University’s Center for Security Studies. “Their desperation has increased appreciably over the past year, as ISIS has stolen their thunder.”

Some noted that an earlier AQAP video, released shortly after the attack, applauded the Kouachis but did not assert responsibility for their actions. With the new video coming a week later, “I would place my bet on this being an after-the-fact claim in order to enhance the prominence and perceived effectiveness of the group, even if they’re not actually behind the operation,” said Paul Pillar of Georgetown, a former CIA specialist in the Middle East.

One of the things intelligence analysts are looking at is “why did it take so long,” the intelligence official said. “Were they caught off guard by the timing and had to quickly scramble and scrape together the video? Or were there some logistic concerns that delayed it? Right now, some are surmising that AQAP might have been caught a little flat-footed.”

Hugh Naylor in Beirut and Adam Goldman and Brian Murphy in Washington contributed to this report.