Gaza rulers Hamas arrested two people over firing rockets into Israel last week, a security source in the Palestinian enclave told AFP.
Israel's army said rockets were launched Thursday from Gaza, the first such military action since three days of cross-border fighting in August.
The incident prompted Hamas's internal security services to detain two people "directly related to the firing of four rockets," said a security source who requested anonymity.
"The Palestinian factions have nothing to do with these rockets, which are aimed at giving the occupation (Israel) an excuse for continuing the aggression," the source told AFP.
The rocket fire was not claimed by any of the armed factions operating in Gaza, which has been ruled by the militant group Hamas since 2007.
It came hours after veteran Israeli hawk Benjamin Netanyahu was declared the winner of a November 1 election, and after an Islamic Jihad fighter was killed by Israeli forces in the West Bank.
The security source did not detail the affiliation of those arrested, adding that the rockets fired were not loaded with explosives.
Palestinian factions have an agreement to coordinate "any response to Israeli aggression", he told AFP.
Israel launched retaliatory strikes Friday on Gaza, which the army said hit a rocket production site belonging to Hamas.