On Friday, around 15 small explosions targeted the homes and vehicles of Fatah officials in Gaza, causing minor damage but no injuries, witnesses and members of Fatah said.
The explosions came days ahead of the 10th anniversary of the death of Yasser Arafat, the late Palestinian president and Fatah leader. One of the targets hit was a stage where Arafat's commemoration is scheduled to be held on Nov. 11.
Fatah and Hamas blamed each other for the blasts, while a letter left at one site claimed responsibility by Islamic State, a claim dismissed by Gaza officials.
"We will not allow the return of internal conflicts, chaos and anarchy to the Gaza Strip," said Eyad Al-Bozom, a spokesman for the Interior Ministry, run by officials loyal to Hamas.
"The security services will pursue anyone who had any connection to these criminal acts until they are brought to justice."
The tensions between Fatah and Hamas, which has dominated Gaza since 2007, have complicated efforts to rebuild the coastal enclave after the July-August war, in which more than 2,100 Palestinians were killed, as well as more than 70 Israelis.