Israel said early Friday it has completed a series of airstrikes on targets linked to the Islamic Jihad militant group in Gaza after overnight rocket fire that rattled a day-old truce. The Palestinian territory’s Hamas rulers, who kept to the sidelines of this week’s fighting, cancelled the weekly protests they organize along the perimeter fence without explanation — apparently in an effort to preserve the calm. Israel reiterated that it was willing to abide by the cease-fire if there are no additional rocket attacks.