NAIROBI, Kenya (CNN) -- "Our objectives are to strike London with low-cost operations that would cause a heavy blow amongst the hierarchy and Jewish communities, using attacks similar to the tactics used by our brothers in Mumbai."
Those are the opening words of a document found on the body of al Qaeda's top East Africa operative when he was killed two years ago.
And the plans uncovered in the document are now even more interesting and relevant in light of the attack on the shopping center in Nairobi, Kenya.
Among the targets identified: the famous Eton College, the five-star Dorchester and Ritz hotels, and the Jewish neighborhood of Golders Green in north London.
The Word document, written in English, which CNN understands was stored on a thumb drive, was found when Fazul Abdullah Mohammed -- architect of the U.S. Embassy bombings in Nairobi and in Dar es Salaam, Tanzania, in 1998 -- was killed at a government checkpoint in the Somali capital, Mogadishu, one night in June 2011. Its contents were first reported by Michelle Shephard of the Toronto Star, who provided the document to CNN.
Richard Barrett, the former head of counterterrorism for MI6, told CNN that while the plans were "pretty aspirational" they were found on "a very determined and extremely able operator who could convert plans to reality" and were seen as a "significant warning" by Western intelligence agencies.
It's not clear whether Mohammed wrote or had approved of the plan. Its style and content suggest that it may have been a "pitch" to him by another al Qaeda operative. Shephard says that it may have been written by a British jihadist in East Africa.
But after the Nairobi attack by the Somali jihadist group Al-Shabaab and other al Qaeda documents seen by CNN, it is further evidence that replicating the 2008 Mumbai, India, attacks has become a major priority for the terror group, aiming at "soft" targets such as hotels, shopping malls, resorts or even cruise ships.
Barrett told CNN that the attack plans discovered in Mogadishu will now be seen in a more concerning light by Western intelligence agencies though "it is open to doubt" that Al-Shabaab would currently have the capability to carry out such an attack in the UK.
In a message to affiliates earlier this month, al Qaeda leader Ayman al-Zawahiri called for "taking the citizens of the countries that are participating in the invasion of Muslim countries as hostages so that our prisoners may be freed in exchange."
Attacking Eton College, where members of the royal family and British aristocracy are educated, would "strike a heavy blow at the 'who's who' of the political and business world," the document said.
"As we know the average English man is envious of the rich and has no ties to the upper class. This attack will totally infuriate the government/royalty but will not have such an impact on the masses," it reasoned.
As for the planned attack on either the Ritz or the Dorchester hotels -- which the author envisaged being carried out on "New Year's, Valentine's Day or even Hanukkah" -- there were further similarities to the attacks in Mumbai and Nairobi.
"We plan to book in advance and take plenty of petrol with the brother, then set the 1st 2nd and 3rd floor on fire using petrol and igniting using petrol bombs ... while we block the stairs so no-one can run down by blocking the staircase with furniture."
The author envisaged using Western recruits to carry out the attack, including British militants who had joined jihadist ranks in Somalia and people put forward by Al-Shabaab.
"For this mission we can use our own people or the harakah (Al-Shabaab) can supply suitable candidates or we would need instant access to all British muhajireen (jihadist emigrants)" the writer said.
"Each martyrdom seeker will be trained in Somalia preferably for 2 months ... the brothers will be pushed through many battles to see how they react under pressure and they will be analysed to see if they can keep their composure."
The training outlined in the document is a chilling precursor to the planning involved in the Nairobi attack.
The brothers "will be trained how to raid a house, clear rooms and gather all hostages in one room also how to use a human shield while shooting and moving through a building," it says.
"Reconnaissance will cover how to gather suitable information on the target, for example where are the nearest police stations, what times is the area most crowded, when are best times to attack, are there any armed guards, are they prepared for an attack, best way to enter building," it continues.
The Al-Shabaab attack in Nairobi closely mirrored the Mumbai attacks, in which members of the Pakistani group Lashkar-e-Tayyiba, a terrorist outfit affiliated with al Qaeda, seized hotels and a Jewish center and held out against Indian security forces for three days. More than 160 people were killed.
The similarities are striking:
• The targets were "soft" -- not military or government facilities, and therefore more easily penetrated;
• They were also enclosed, making it more difficult for security forces to flush out the assailants;
• A similar number of attackers -- about 10 -- was involved, and they used multiple entrance points;
• Both attacks were low-tech, involving automatic weapons and hand grenades, at the opposite end of the terror spectrum from the 9/11 attacks;
• Both involved a significant amount of preparation.
• They were in major cities, in places that attracted foreigners, and especially Westerners, and they focused on neighboring countries regarded as hostile. The Pakistani group attacked Indian targets; the Al-Shabaab cell attacked a Kenyan landmark in retaliation for Kenya's incursion into and occupation of southern Somalia;
• Israeli or Jewish interests were part of the targeting matrix;
• The attacks were geared to gaining maximum publicity.