How many bombs were used in the attack that killed Tim and Jonathan Ball?
The Tim Parry Johnathan Ball Foundation for Peace:  It was formed in 1995 by Colin and Wendy Parry, following the loss of their 12-year-old son Tim and 3-year-old Johnathan Ball in the 1993 Warrington bomb attacks, which were perpetrated by the Provisional Irish Republican Army. Warrington bomb attacks:  The second attack happened on 20 March, when two small bombs exploded in litter bins outside shops and businesses on Bridge Street.
two small bombs