The incident took place near the northern border of the Palestinian enclave, from where Islamic Jihad militants had launched rockets at Israel.
A five-month-long truce between Gaza militants and Israel has been put in jeopardy since Israeli troops went into the enclave late on Tuesday to destroy a border tunnel which they said had been dug as part of planned operations to abduct its soldiers.
A Palestinian militant was killed in the clash that followed, prompting a mortar barrage of Israel by militants. An Israeli airstrike then killed another five militants preparing another mortar strike.
In retaliation, Palestinian militant groups, including the ruling Hamas, which seized power in Gaza in the summer 2007, embarked on an extensive bombardment of southern Israel. However, no victims or damage were reported and the attacks have now subsided.
Israeli Defense Minister Ehud Barak said his country did not intend to violate the truce, but would act to eliminate threats to Israeli soldiers.
