The attack on India's financial capital bears all the trademarks of al-Qaida — simultaneous assaults meant to kill scores of Westerners in iconic buildings — but clues so far point to homegrown Indian terrorists, global intelligence officials said Thursday.
Spy agencies around the world were caught off guard by the deadly attack, in which gunmen sprayed crowds with bullets, torched landmark hotels and took dozens of hostages.
"We have been actively monitoring plots in Britain and abroad and there was nothing to indicate something like this was about to happen," a British security official told The Associated Press on condition of anonymity because of the sensitivity of his work.
Britain is the former colonial power in India and Pakistan and closely monitors terrorist suspects in those countries.
In some ways, the attack illustrated just how fluid terrorist tactics have become since Sept. 11, 2001 — and how the threat has become more global. Al-Qaida's leaders on the Afghanistan-Pakistan border still provide inspiration but groups are becoming increasingly local.
The group that claimed responsibility, Deccan Mujahideen, was unknown to global security officials. The name suggested the group was Indian.
One of the attackers reportedly called an Indian television station, speaking the main Pakistani language of Urdu, to demand the return of Muslim lands. That was a reference to Kashmir, territory claimed by both India and Pakistan.
But Ajai Sahni, head of the New Delhi-based Institute for Conflict Management who has close ties to India's police and intelligence, said the attack was a departure from past assaults waged over Kashmir. Other such attacks had targeted Indian legislators, not Westerners.
Young Islamic extremists?
Security officials said it was too soon to make a connection to Pakistan.
"It would be premature ... to reach any hard-and-fast conclusions on who may be responsible for the attacks, but some of what we're seeing is reminiscent of past terrorist operations undertaken by groups such as Lashkar-e-Taiba and Jaish-e-Mohammed," a U.S. counterterrorism official said on condition of anonymity, referring to Pakistani militant groups linked to al-Qaida who have fought Indian troops in Kashmir.
Another British security official told the AP on condition of anonymity that the attack doesn't look to have been directed by al-Qaida's core leadership, which has been weakened by the deaths of several leaders and key operatives in recent months.
Al-Qaida's core leadership is believed to be fewer than 100 people now, said Rohan Gunaratna, author of "Inside Al-Qaida" and a terrorism expert at the International Center for Political Violence and Terrorism Research in Singapore.
The British security official said it appeared the attack was inspired by Islamic extremist ideology and al-Qaida propaganda popular among radicalized youths. Many of the attackers in the Mumbai assault were young.
Gunaratna said he believed the group that carried out Wednesday's attack was the Indian Mujahideen, responsible for past attacks in Mumbai.
The word "Deccan" refers to a plateau in southern India. "Mujahideen" refers to holy warriors.
"The earlier generation of terrorist groups in India were mostly linked to Pakistan," Gunaratna told the AP. "But today we are seeing a dramatic change. They are almost all homegrown groups. ... They are very angry and firmly believe that India is killing Muslims and attacking Islam."
British-based Jane's Information Group said it thought the attackers could be Indian but that taking hostages suggested a wider anti-Western agenda.
"Until now, terrorist attacks in India have targeted civilians, often in busy market or commercial areas, and in communally sensitive areas with the intention to foment unrest between Hindu and Muslim communities," said Urmila Venugopalan, Jane's South Asia analyst.
"This stands in contrast to the national issues that appeared to motivate Indian Mujahideen," Venugopalan said.
Indian Prime Minister Manmohan Singh blamed "external forces" but stopped short of blaming Pakistan. Both are nuclear-armed countries.
In September, a massive suicide truck bomb devastated the Marriott Hotel in the Pakistani capital, Islamabad, killing at least 54 people, including three Americans and the Czech ambassador.
"This type of terrorism is spreading, through Pakistan and now India, but we were all surprised by such a large-scale attack like this," said Wajid Hassan, Pakistan's High Commissioner in London. "This is no coincidence that this type of attack happened so soon after the bombing of the Marriott Hotel. People from all countries are being paid to fight this al-Qaida war. This is a war that goes beyond any nationality."
Sahni, however, said "very preliminary investigations and intelligence information would suggest that some groups based in Pakistan are the most likely.
"If there is Indian participation, it's most likely to be Students' Islamic Movement of India," he said, referring to a radical student group banned in India in 2001.
Indian intelligence officials were also investigating whether Mumbai's criminal underworld could be involved.
"It's a possibility," Sahni said. "When we say Mumbai underworld we're talking of Dawood Ibrahim."
Ibrahim is one of India's most wanted men and also the alleged mastermind behind bombings in Mumbai in 1993 that killed 257 people. He has reportedly fled Mumbai, and police now believe he lives in Pakistan. Pakistani officials have denied this.
Interpol, the global police organization, was sending a team to assist in the Mumbai investigation, NBC reported.