http://www.tribuneindia.com/2005/20050709/main2.htm
"officials said the 3 blasts which ripped through underground trains seem to have been caused by package bombs left by attackers who fled and detonated them by timers, not mobile phones or other remote triggers.
The bombs which killed 191 people on trains in Madrid in March 2004 were triggered by mobile phones."
I'm starting to suspect it was the work of a copycat.
I want to know the type of explosives used in each case and if they were a different type.
"The London Police said it received no warning of the attacks, which the government said bore the hallmarks of the Islamic militant Al-Qaida network."
...IOW, no warning = Al-Qaida(!). Does the IRA always warn?