The expert orchestration of the explosions would be evident from the following timings of different explosions:

Khar -- 1824 hours
Bandra -- 1824 hours
Jogeshwari -- 1825 hours
Mahim -- 1826 hours
Mira Road -- 1829 hours
Matunga -- 1830 hours
Borivali -- 1835 hours

Thus, all the seven explosions have taken place with a time span of 11 minutes following each other in quick succession.

No information is as yet available on the explosives or detonators used or how the explosions were triggered off. As of now, there is no reason to believe that suicide terrorists were involved. While there are as yet no indicators of the likely trigger mechanism, there are only three possibilities -- a mechanical timer, a chemical timer and a mobile telephone.

Chemical timers of US origin given to Pakistan during the 1980s were used in the Mumbai blasts of March 12, 1993.

In the Coimbatore serial blasts of February 14, 1998, mechanical timers of local improvisation were used.

Mobile telephones, which were reportedly used in the Madrid train blasts of March 11, 2004, by pro-Al Qaeda Salaqfi terrorists, have not so far been used in India for serial blasts. They provide a remotelly controlled mechanism for well-timed explosions within a narrow time frame as we witnessed on July 11, 2006.

Precision timing is generally difficult to achieve with mechanical and chemical timers. A wider time span would be required.

This is the third instance of mass casualty terrorism in the history of terrorism in India.

The first was the blowing up of an Air India aircraft (the Kanishka) on June 23, 1985 off the Irish coast by the Babbar Khalsa, a Sikh terrorist organisation. 325 people were killed.

The second was the Mumbai blasts of March 12, 1993,in which 250 people were killed in 13 well-coordinated explosions directed against well-chosen economic targets by a group of Muslims trained and armed by Pakistan's Inter-Services Intelligence agency, with the assistance of Dawood Ibrahim [Images], an Indian gangster presently living in Pakistan. The perpetrators were carefully selected Muslim youth not belonging to any jihadi organisation.

This is the fourth instance of coordinated serial blasts. The first was in June 1985, when some Sikh terrorists placed transistor radio sets filled with small quantities of explosives in different parts of New Delhi. When passersby picked up the radio sets and switched them on, the explosions took place.The casualties were small.

The second was the Mumbai blasts of March 12, 1993, and the third the Coimbatore blasts of February 14, 1998, in which 33 people were killed and 153 others were injured in a series of 12 bomb blasts.

The explosive material (RDX) used on March 12, 1993 were given to the perpetrators by the ISI. That used on February 14, 1998, was procured by the perpetrators locally.

This is the second instance of multiple explosions on trains. The first was carried out by the Students Islamic Movement of India, SIMI, on December 6, 1993, coinciding with the first anniversary of the demolition of the Babri Masjid in Ayodhya in Uttar Pradesh by a Hindu mob. Those were random explosions and not well-coordinated serial explosions. The casualties were small.

Jihadi terrorism in Indian territory outside Jammu and Kashmir [Images] is a post-1992 phenomenon and is attributable to the feelings of hurt and anger caused in the Muslim community -- particularly Muslim youth -- by the demolition of the Babri Masjid. The feelings of hurt over the demolition of the masjid are aggravated from time to time by feelings of anger over police atrocities against Muslims and over police failure to protect Muslims.

A third cause for anger since July last year has been India's close relations with the US and the Government of India's perceived failure or reluctance to express itself openly and in strong language against the violations of human rights of the Muslims by the US.

Such feelings of anger have resulted in a series of acts of reprisal terrorism since 1993. These acts have been carried out by some angry Indian Muslims manipulated by Dawood Ibrahim and the ISI; indigenous Muslim organisations with proved links to the ISI like the SIMI; and indigenous Muslim organisations such as the Al Ummah in Tamil Nadu with no proved links to the ISI.

Some Indian Muslims were responsible for the serial blasts of March 12, 1993 and February 14, 1998. One should not be surprised if there is an involvement of some Indian Muslims in the blasts of July 11, 2006, too.

More serious have been the acts of reprisal terrorism organised in the Indian territory outside Jammu and Kashmir since 1993 by Pakistani jihadi organisations. The Lashkar-e-Tayiba, the Harkat-ul-Mujahideen, the Harkat-ul-Jihad-al-Islami and the Jaish-e-Mohammad have been involved in these acts, which were inspired and orchestrated by the ISI. All of them are members of Osama bin Laden's International Islamic Front For Jihad Against the Crusaders and the Jewish People formed in February 1998. These organisations have been operating from their bases in Pakistan, Bangladesh and the Gulf countries. They have not so far organised multiple, well-timed explosions.

Of these, the Lashkar has had the widest network in north and south India. The Harkat-ul-Jihad-al-Islami has been showing signs of developing a similar network in the north and the south. The Harkat-ul-Mujahideen and Jaish network is believed to be restricted to north India.

While the Pakistani organisations with their objective of 'liberating' Indian Muslims from the control of the Hindus have enjoyed some support from Indian Muslim youth, Al Qaeda [Images], with its pan-Islamic objective of forming an Islamic caliphate, had not enjoyed any noticeable support in the Indian Muslim community in the past. However, taking advantage of the anger among sections of Indian Muslims over the relations with the US, Al Qaeda has been trying to rally the Muslims of India in its support.

Since 2003, Ayman al-Zawahiri, the no 2 in Al Qaeda, has been critical of India and the Hindus. Since President George W Bush's [Images] visit to India in March 2006, bin Laden has joined this criticism. Before March 2006, Al Qaeda and bin Laden used to talk of a Crusader-Jewish conspiracy against Islam. Since March 2006, they talk of a Crusader-Jewish-Hindu conspiracy against Islam.

Al Qaeda has been critical of India's strategic relations with the US and of what it projects as US support to India on the Kasmir issue. But it has been silent on the India-US nuclear deal and on India's vote against Iran on the nuclear issue at the International Atomic Energy Agency at Vienna.

The July 11 blasts have coincided with the following events: The first anniversary of the abortive terrorist strike by jihadi terrorists against the improvised Hindu temple at Ayodhya on July 5 last year; the first anniversary of the visit of Prime Minister Manmohan Singh [Images] to the US on July 18 last year; and the forthcoming G-8 summit in St Petersburg [Images] in Russia [Images] later this week where Dr Singh is expected to meet Mr Bush and review India-US relations.

The blasts have also come at a time of renewed tension in the relations between sections of the Hindu and Muslim communities in Mumbai and signs of unhappiness in sections of the Indian Muslim community over the Manmohan Singh government's decision to provide extra protection to an improvised Hindu temple at Ayodhya. Some Muslims look upon this improvised temple as having been constructed by Hindus on land belonging to the commmunity over which the demolished Babri Masjid stood.

While in the past, the Pakistani pan-Islamic organisations and the ISI have taken advantage of the pockets of anger in the Indian Muslim community for their strategic objectives against India, since March Al Qaeda has been trying to take advantage of them for its pan-Islamic and anti-US objectives. In view of the increased interactions between the US and India, it is likely to look upon India as providing a fertile soil for its anti-US operations.

The impact of Al Qaeda's propaganda and ideology on the minds of some Indian Muslim youth, its possible inspiration behind the blasts of July 11 and likely threats to American interests in India need close attention.

The Madrid blasts of March 2004 were preceded by strong anti-Spain propaganda by Al Qaeda. The London [Images] blasts of July 7, 2005 were preceded by strong anti-UK propaganda. Al Qaeda's anti-India statements since March 2006 need to be closely monitored and not dismissed lightly as of no consequence.