MUMBAI, India - Police in India said Tuesday they had identified the nine suspected Islamic militants killed during the three-day siege of Mumbai and uncovered new details about them -- including their hometowns in Pakistan.

The new information, which included three gruesome photos of maimed faces, appeared to bolster India's claims that all the attackers were from Pakistan.

Mumbai's chief police investigator Rakesh Maria also showed photos of eight of the men -- some from identity cards, while others were gruesome shots of the dead attackers. The body of the ninth, he said, was too badly burned.

Most of the attackers came from Pakistan's Punjab province, and all were between the ages of 20 and 28.

India has blamed the Pakistani-based militant group Lashkar-e-Taiba for the attacks that left 171 people dead in India's financial centre last month, and have demanded that Pakistan take action.

Maria did not say how police had tracked down their hometowns, although they have been interrogating the lone surviving gunman.

Maria said the leader of the group was Ismail Khan, 25, from Dera Ismail Khan, a city in Pakistan's North West Frontier Province, who he called veteran of other Lashkar attacks. He did not provide details.

Khan led the assault on Mumbai's busy railway station.

Pakistan has intensified its crackdown on Lashkar-e-Taiba by arresting 20 more people but said Tuesday it will not hand any of its citizens over to India.

The United States also is pressing Pakistan to help catch those behind the attack, and avert a crisis between the nuclear-armed neighbours that would harm efforts against the Taliban and al-Qaida.

However, police only had first names and aliases for some of the gunmen. Maria said the men had been introduced to each other by their aliases, but during the operation had told each other their real names.

The youngest attacker was identified as 20-year-old Shoaib, alias Soheb, who came from Narowal district in Pakistan's Punjab province. He was among those who attacked the Taj Mahal hotel, Maria said. Two came from the central Pakistani city of Multan, Maria said.

Some of the photographs were taken from identity documents found on the dead gunmen, while others were pictures taken of the bodies. Some had charred faces, while others were swollen and battered.

Officials at Pakistan's Foreign Ministry could not be reached immediately for comment, though President Asif Ali Zardari said last week that he doubted the captured gunman was a Pakistani.

There have been signs that the attackers may have had help from within India. Maria said police were bringing a man, identified only as Sabauddin, to Mumbai for questioning along with Indian national, Faheem Ansari.

Sabauddin was arrested in north India with Ansari in February. Ansari was carrying hand-drawn sketches of hotels, the train terminal and other sites in Mumbai that were later attacked. The two have been in an Indian jail since then.

Maria gave no other information on Sabauddin, including his nationality.

Also Tuesday, Maria said the captured gunman, Mohammed Ajmal Kasab, had asked to be allowed to write a letter to his father in which he expressed regret for carrying out the attacks.

In the letter, written in Urdu, Kasab said "he has been misled by these people," Maria said, apparently referring to those who recruited him. "Youngsters in the village should be told not to believe in this indoctrination," Maria said, reading from a copy of the letter.