Hamas did not provide any evidence of Israeli involvement. The Israeli military, asked about the explosion in Gaza, said it did not comment on foreign reports.
The car bombing came as rival factions are trying to implement a new agreement meant to end a 10-year rift that has effectively split the Palestinian territories between Hamas in Gaza and the more mainstream Fatah in the occupied West Bank.
Hamas dissolves Gaza administration in Palestinian unity bid
It also coincided with a Hamas crackdown on radical Salafi groups in Gaza which are opposed to the Palestinian rapprochement.
Fatah condemned the attack. Tawfeeq Abu Naeem, Hamas' head of security in Gaza and a strong supporter of the reconciliation deal, was slightly wounded when his car exploded outside a mosque, Hamas said.
Hamas' deputy chief in the territory, Khalil Al-Hayya, said Israel was behind the attack and trying to destabilise the reconciliation deal agreed upon earlier this month.
Hamas offers clemency to Israeli 'collaborators' after killing
Israel has said it will engage with a unified Palestinian government only if Hamas agrees to international demands that include giving up its weapons and stopping its call for Israel's destruction.
Hamas has angered Salafi groups by stepping up a security crackdown and recently detained a senior operative. It also has improved ties with Egypt, which is battling militants across the border in the Sinai peninsula.
New Hamas document accepts Palestinian state with 1967 borders
Some disputes arose this week in implementing the reconciliation deal, which calls on Hamas to cede administrative control of Gaza.
Senior Fatah officials travelled to Gaza this week from the West Bank to take control of two government offices there, but they turned back, saying Hamas officials refused their authority. A Fatah spokesperson later said the issue was being resolved.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ