The bus exploded right at the moment it began to turn away from Sharon's compound. I am pretty sure it was a message to Sharon. Seems every time Sharon tries to make peace, someone or someone's die. Wish Sharon would understand the message someday.
Islam is a religion of death, anybody that reads the Koran or the stories of Mohammad can see that. Nobody can make peace with them, it is against their religion. It is clearly spelled out that treaties are only for rearming for the purpose of slaughtering those you make treaties with.
You want peace with Islam, you must kill them.