Assailants have detonated a bomb outside a popular cafe in Gaza City in what appears to be part of an extremist campaign against targets seen as signs of Western influence. There were no casualties in Sunday's explosion. But the blast smashed the cafe's windows and damaged its door. Owner Khalid Harbid says another bomb went off outside his cafe last month. He blames Gaza's Islamic Hamas rulers for not protecting his business. A Hamas official said only that police are investigating.