FBI agents made an urgent trip to India and Pakistan last week after they learned of plotting for Mumbai-style terrorism attacks while investigating a Chicago man’s case, according to current and former U.S., Indian and European counter-terrorism officials.

The man, David Coleman Headley, was recently charged with being a longtime clandestine operative for Lashkar-e-Taiba and another Pakistan-based militant group affiliated with Al Qaeda.

The alleged plots, believed to be in the works for months, were aimed mostly at locations frequented by Americans, Israelis and other Westerners, such as hotels or synagogues, according to the officials. India’s National Defense College and other government sites were scouted as possible targets as well, according to the officials and FBI affidavits recently unsealed in Chicago.

The investigators say that Headley, who is now cooperating with the FBI, spent much of the last few years scouting targets not only for last year’s Mumbai siege in which 166 people died, including six Americans, but also for future attacks in India and one in Denmark.

Authorities allege that he did so at the direction of two senior operatives of Pakistani militant groups who had also been members of Pakistan’s military.

The Justice Department last week filed criminal terrorism charges against a third former Pakistani army officer, still in Pakistan, in the Denmark plot.

On Dec. 9, Headley pleaded not guilty to the charge that he worked with Lashkar-e-Taiba to plan the Mumbai attacks.

The accusations implicating former Pakistani military officers are almost certain to exacerbate tensions in the region. Washington and India contend that Pakistan’s military maintains close ties to Lashkar and other militant groups and has used them for attacks on India. Pakistan has long denied those accusations and demanded proof.

Nadeem Kiani, a spokesman for the Pakistan Embassy in Washington, downplayed the significance of any role by former military officers in Lashkar terrorism strikes or plots, saying, “A former army officer doesn’t represent the army.”

He added that the Islamabad government had been actively cooperating with the United States and India in the various investigations. Any evidence showing that former Pakistani officers were involved with terrorists “should be shared with Pakistan, and we will look into it,” Kiani said.

U.S. officials believe that the FBI investigation now has documented such ties, citing phone intercepts, travel records, credit card purchases and other information in the Headley investigation.

In the recently unsealed court documents, authorities say Headley traveled widely through India with a video camera posing as an American Jew. After each surveillance mission, they allege, he took a circuitous route to Pakistan to brief his Lashkar handlers and turn over the tapes before heading back home to Chicago.

Various sources of information appear to have corroborated the FBI’s findings.

“There have been a number of intelligence reports indicating [Lashkar] activities that might suggest further attacks” in India, one South Asia-based Western official confirmed.

In response, the Israeli National Security Council’s counter-terrorism bureau recently issued two “highly concrete” travel warnings about possible Lashkar terrorist attacks in India with Israelis and Westerners as targets. One mentioned synagogues, Chabad Houses and popular Israeli tourist spots in the coastal state of Goa.

Indian authorities have been on high alert since getting briefed by U.S. officials. Last month, the current threat level was a prime topic of discussion during Prime Minister Manmohan Singh’s meeting with President Obama in Washington, U.S. officials said.

The initial leg of the FBI trip to Mumbai and then New Delhi was based, in part, on orders from the White House that agents share as much information from the investigation as possible with India about when and where such an attack may occur.

Information was also shared about the role Headley and his alleged co-conspirators in the United States, Pakistan and Europe may have played in the Mumbai attacks of Nov. 26, 2008, when 10 heavily armed gunmen rampaged throughout India’s financial capital, targeting luxury hotels, transportation centers, a hospital and a Jewish community center.

The trip by agents of the FBI’s Chicago field office was also designed to help India fill in the still-significant gaps in what it knows about the Mumbai massacre and the growing global threat posed by Lashkar, also known as LET, the officials said.

The agents’ purpose on the last leg of the trip was more politically delicate: to present Pakistan with new hard evidence that Lashkar is plotting attacks from its soil despite the Islamabad government’s promises to crack down on the group -- and that Lashkar is doing so with the help of some former and possibly current high-ranking military officers.

The FBI alleges that Headley was trained by Lashkar operatives in 2002 and told to change his name from Daood Gilani in 2006 so he could travel without attracting suspicion. Lashkar-e-Taiba, which means Army of the Pure, has been designated a terrorist group by the U.S. government.

Headley, 49, was arrested Oct. 3 before boarding a plane in Chicago, intending to travel to Pakistan. He was initially charged with plotting terrorist attacks in Denmark. His friend, Tahawwur Hussain Rana, 48, who ran an immigration consulting business that employed Headley, was later charged with terrorism conspiracy in the alleged plot against the Danish newspaper Jyllands Posten, which previously published controversial cartoons of the Muslim prophet Muhammad.

Authorities are now scrambling to determine whether Headley and Rana had other co-conspirators in the United States and overseas.

“There’s something missing, which is what he was trying to do here,” one senior U.S. counter-terrorism official said of Headley, the son of a Pakistani diplomat and an American-born mother. Headley converted to Islam later in life. “He travels under the radar, he looks white, and he’s older,” unlike most would-be jihadists, who are usually half his age.

“Clearly, now we know in hindsight that he’s in contact with known LET contacts,” said the official.

Headley also was working at the direction of Ilyas Kashmiri, a leader of another militant group who sits on Al Qaeda’s shura, or leadership council, said the official.

(U.S. authorities do not believe Headley was connected to five students from Virginia who were arrested last week in Pakistan and accused of trying to join a Pakistani militant group. According to Pakistani police officials, the students also tried to link up with Lashkar, but the security-conscious group rebuffed them because they didn’t have the proper sponsors.)

Headley spent as much as a year total in India, including stays at five-star hotels and membership at an ultra-luxury gym frequented by Bollywood movie stars, according to interviews and the U.S. court documents.

“Where did he get the money for all of this?” asked Bahukutumbi Raman, the former head of counter-terrorism for India’s foreign intelligence agency. “He got it from LET, of course, but the FBI should be asking questions about the role of the ISI,” or Pakistan’s Inter-Services Intelligence military spy agency.

The FBI affidavits filed in support of the Headley and Rana prosecutions mark the first time U.S. authorities have accused former Pakistani military officials by name of being involved in terrorism.

Based on wiretaps and Headley’s cooperation, prosecutors have charged retired Pakistani army Maj. Abdur Rehman Hashim Syed with being a key facilitator of Headley’s alleged terrorism plot in Denmark.

The FBI documents allege, in great detail, how Rehman acted as a conduit between Headley and the leaders of Lashkar and to Kashmiri. Kashmiri is a former Pakistani special forces commando, U.S. officials believe.

In court documents and interviews, they identify another retired Pakistani army officer, Maj. Haroon Ashiq, as having kidnapped affluent people to raise money for Kashmiri’s group and having killed a rival army major general who had threatened to expose links between the army and militant groups.

And potentially of most concern, authorities alleged that Headley’s Lashkar handler in the plotting for Mumbai was another former Pakistani army senior officer. He is not identified by name in the court documents, but U.S. and Pakistani officials said that he is Sajid Mir, a top Lashkar operative who they believe orchestrated Headley’s role in all of the India plots, including last year’s attack in Mumbai.

Such disclosures may prove embarrassing for Pakistan, but probably not enough to force the Pakistan military to sever its ties with Lashkar and other militant groups, some current and former officials said.

“LET is an extremely dangerous group and well-connected to the Pakistan government,” said one Justice Department counter-terrorism official. “There is a civil war going on, and it’s not clear if our side is going to win.”

josh.meyer@latimes.com