India's top law enforcement official apologized for "lapses" that allowed 10 suspected Islamic militants to rampage through Mumbai, while the prime minister pressed the assertion that Pakistani extremists were behind the attack.

Home Minister Palaniappan Chidambaram acknowledged the failings but stressed the country is bolstering security following the assault that left 171 dead and 239 wounded in the country's financial capital.

"There have been lapses. I would be less than truthful if I said there had been no lapses," Chidambaram told reporters.

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The minister, who assumed his post just days ago following the ouster of the previous minister in the attack's aftermath, spoke as details surfaced that a Pakistani militant group had used an Indian operative as far back as 2007 to scout targets in the Mumbai plot.

Linking an Indian national to the plot undermines India's argument that Pakistani "elements" were solely responsible for the Nov. 26-29 attacks. It also adds to a torrent of criticism about missed warnings and botched intelligence.

Prime Minister Manmohan Singh reasserted the charge Friday that Pakistan-based extremists were responsible.

"The territory of a neighboring country has been used for perpetrating this crime," Singh said. "We expect the international community to wake up and recognize that terror anywhere and everywhere constitutes a threat to world peace and prosperity."

Mohammed Ajmal Kasab, 21, the surviving gunman, told interrogators he had been sent by the banned Pakistani militant group Lashkar-e-Taiba and identified two of the plot's masterminds as being involved, two Indian government officials familiar with the inquiry said. Police had earlier identified the prisoner as Ajmal Amir Kasab.

Lashkar-e-Taiba changed its name to Jamaat-ud-Dawa after it was banned in 2002 amid U.S. pressure, according to the U.S. State Department. The U.S. lists both groups as terrorist organizations.

Hafiz Mohammed Saeed, who heads Jamaat-ud-Dawa — though U.S. authorities in May described him as the overall leader of Lashkar-e-Taiba — denied in an interview that there was a Pakistani hand behind the attacks. He called on Indian authorities to act like "a responsible country." Saeed is considered the founder of both groups.

"The Indian leadership is using Pakistan as a punching bag to cover its failures at home," Saeed told Outlook magazine in an interview released Friday. "Instead of blaming Pakistan, India should have acted as a responsible country, shown patience and focused on investigating the attacks to find out the real culprits."

"I can say with authority," he continued, "that the Lashkar does not believe in killing civilians."

The interview was conducted in Lahore on Wednesday with the magazine's foreign editor, Aijaz Ashraf.

Kasab told police that a senior Lashkar leader, Zaki-ur-Rehman Lakhvi, the group's operations chief, recruited him for the attack, and that the assailants called another senior leader, Yusuf Muzammil, on a satellite phone before the attacks.

The information sent investigators back to another reputed Lashkar operative, Faheem Ansari.

Ansari, an Indian national, was arrested in February in north India carrying hand-drawn sketches of hotels, the train terminal and other sites that were later attacked in Mumbai, Amitabh Yash, director of the Special Task Force of the Uttar Pradesh police, said Thursday.

During his interrogation, Ansari also named Muzammil as his handler in Pakistan. He claimed to have trained in a Lashkar camp in Muzaffarabad — the same area where Kasab said he was trained, a senior police officer involved in the investigation said.

In Pakistan, the Interior Ministry chief told reporters he had no immediate information on Lakhvi or Muzammil.

According to the U.S., Lakhvi has directed Lashkar operations in Chechnya, Bosnia and Southeast Asia, training members to carry out suicide bombings and attack populated areas. In 2004, he allegedly sent operatives and funds to attack U.S. forces in Iraq.

Lashkar, outlawed by Pakistan in 2002, has been deemed a terrorist group with ties to al-Qaida by the U.S. The group has derived some of its funding from organizations based in Saudi Arabia and Kuwait, with its leaders making fundraising trips to the Middle East in recent years, U.S. officials say.

Islamist charity Jamaat-ud-Dawa, accused by the U.S. of being the front group for Lashkar, on Thursday denied any connection to the attacks.

"It is true we had links with Lashkar-e-Taiba in the past, but please remember, the past is the past," said Abdullah Muntazir, spokesman for the group, based on the outskirts of Lahore, Pakistan. "We are the victim of baseless Indian propaganda, we are not involved in attacks in India, we are just doing welfare work and nothing else."