I was in Manila Valentines Day 2005 when 3 bombs went off almost simultaneously one at the Intercontinental, the Hotel I was staying in, and a couple of other locations around the city. If I recall the attacks killed 10 or 15 and a couple of hundred injured. Adu Sayyaf, the Muslim separatists from the south, claimed responsibility almost immediately.
This doesn't really sound like Muslim terrorism to me...not well enough planned or executed. Bombs are the Muslim weapon of choice in that part of the world and multiple locations are the MO...lone gunman are very rare as few in the population have access to private firearms...