According to Pakistan's The News, Inter Services Public Relations is denying that anyone was arrested:
RAWALPINDI: The Pakistan Army has rejected claims in the US media that the country's top intelligence agency ISI arrested some of the Pakistani informants who fed information to the Central Intelligence Agency (CIA) in the months leading up to the raid that led to the death of Osama bin Laden. A statement released by the ISPR read that no arrests were made and no major was being investigated in reference to the Abbottabad raid.I am not going to sit here for the rest of the morning and add more updates on denials and corrections to denials, so this is the last update.
UPDATE 5:00 AM EDT
The number of those arrested has gone up from the number cited in the NYT report, which broke the story (see below):
Pakistan Arrests 30 Civilians in Probe of U.S. Raid That Killed Bin LadenUPDATE 1:54 AM EDT
By Haris Anwar - Jun 15, 2011 4:14 AM EDT
Pakistan arrested 30 to 40 civilians as it investigates the U.S. commando raid that killed Osama bin Laden last month, an army spokesman said, denying a report that an army major was among those detained.
Some of those arrested have already been released, Brigadier Azmat Ali, director of public relations at the army’s media arm in Rawalpindi, said in a phone interview.
A report in the New York Times that an army officer is being held is “totally wrong,” Ali said. “I can say with authority that all arrests were non-military.”
Pakistan’s top military spy agency has arrested five Pakistani informants who fed information to the Central Intelligence Agency in the months leading up to the raid that killed bin Laden on May 2, the Times reported today, citing American officials it didn’t name.
Those arrested include a Pakistani army major who officials said copied the license plates of cars visiting bin Laden’s compound in Abbottabad, the report said.
From Reuters about 50 minutes ago: "Asked about the Times report [see below], a CIA spokeswoman neither confirmed nor denied it and said she had no further comment."
By ERIC SCHMITT and MARK MAZZETTI
Published: June 14, 2011 [published online at approx. 11 PM EDT]
The New York Times
WASHINGTON — Pakistan’s top military spy agency [ISI] has arrested some of the Pakistani informants who fed information to the Central Intelligence Agency in the months leading up to the raid that led to the death of Osama bin Laden, according to American officials.
Pakistan’s detention of five C.I.A. informants, including a Pakistani Army major who officials said copied the license plates of cars visiting Bin Laden’s compound in Abbottabad, Pakistan, in the weeks before the raid, is the latest evidence of the fractured relationship between the United States and Pakistan.
The fate of the C.I.A. informants arrested in Pakistan is unclear, but American officials said that the C.I.A. director, Leon E. Panetta, raised the issue when he travelled to Islamabad last week to meet with Pakistani military and intelligence officers.
[...]The rest of the Times report doesn't throw more light on the situation so here I'll switch to the Associated Press, which unearthed another factoid connected with the situation:
AP sources: Pakistan nabs CIA informants
By KATHY GANNON [reporting from Islamabad]
[Published approx. midnight EDT]
WASHINGTON (AP) — Pakistan's intelligence service has arrested the owner of a safe house rented to the CIA to observe Osama bin Laden's compound before the U.S. raid that killed the al-Qaida leader, as well as a "handful" of other Pakistanis, a U.S. official said late Tuesday.
In Pakistan, a Western official confirmed a New York Times report [see above] that five of the Pakistani informants who fed information to the CIA before the May 2 raid were arrested by Pakistan's top military spy agency.
The officials spoke to The Associated Press on the condition of anonymity to discuss sensitive intelligence matters.[...]