The raids came hours after Palestinian fighters fired two rockets at southern Israel without causing damage or deaths, according to a military spokesman.
Shalit talks fail
The Israeli raids came after reports that indirect talks between Israel and Hamas over a prisoner swap to free Gilad Shalit, a captured Israeli soldier, had failed.
Shalit was captured by Gaza groups in a 2006 cross-border raid.
Osama al-Muzaini, a Hamas official who is involved in the negotiations, said on Friday that the talks had shown little progress and that any claims by Israel that progress had been made were "election-motivated".
"There has been no progress in the [Shalit] file for several months and that is because [Israel] remained unwilling to pay the price," he told the Reuters news agency.
Muzini was responding to a report published on the website of Israel's Haaretz newspaper quoting unnamed Israeli officials as saying significant progress had been made in truce talks and Shalif's freedom.
Muzaini did not mention where the talks had been held or who led the mediation.
Hamas has demanded the release of 1,400 prisoners in exchange for Shalit.
Muzaini said Israel had only agreed to 71 names from the list of 450 long-serving prisoners Hamas had proposed more than a year ago.