Ibrahim Salah, a spokesman for the ministry, urged Fatah to assist in the search for suspects in the attack, the Ma'an news agency reported. In a statement, Salah said Fatah should resolve its differences.
Gaza has been in control of Hamas effectively since 2007 while Fatah controls the West Bank.
The attacks began in April when someone set fire to the car of Mahmud Hussein, secretary-general of Fatah in Gaza. On Monday, a bomb was placed under the car of Monther al-Bardawil, Fatah official, and on Wednesday a car belonging to Khaled Musa, a Fatah leader, was damaged.