Tunnels are used to smuggle weapons as well as more everyday items
Israeli jets have attacked parts of southern Gaza, after Palestinian militants fired a mortar at Israel.
Israel's military said the strikes targeted seven smuggling tunnels from Egypt into Gaza and a Hamas security post in Khan Younis.
There were no reports of casualties from Wednesday's pre-dawn raids.
There have been sporadic rocket fire and Israeli raids since unilateral ceasefires last month ended a 22-day assault by Israel on the Gaza Strip.
Around 1,300 Palestinians, including 400 children, and 13 Israelis were killed in the fighting.
Israel's offensive targeted the Islamist Hamas group which controls the Gaza Strip, and was also intended to limit the number of militant rockets fired into southern Israel by destroying weapons smuggling tunnels along Egypt's border.
Hamas wants Israel to lift its blockade of the coastal enclave, and Egyptian mediators are negotiating talks between the two sides, which include an extended ceasefire, the opening of Gaza's border crossings and a possible prisoner swap.
On Tuesday, Israel's Prime Minister Ehud Olmert reiterated that the blockade would only be lifted if Gilad Shalit - an Israeli soldier captured by Gaza militants in 2006 - was released, a condition that Hamas has previously rejected.
Israel's cabinet is expected to discuss the mooted deal later on Wednesday.