Palestinian medics say Israeli forces raided the southern Gaza Strip early Thursday, killing at least eight Palestinians, including a child.
Witnesses say at least 26 Palestinians were wounded in Israel air strikes and artillery fire near the town of Rafah.
They say four militants were among those killed.
The Israeli military says its aircraft fired missiles at a group of militants preparing to attack soldiers operating in the area.
Residents say Israeli troops in armored vehicles and about 50 tanks took up positions near Gaza's closed airport - the furthest Israeli incursion in its offensive against Palestinian militants.
Israel says the offensive, which began more than a month ago, is aimed at stopping Palestinian rocket attacks into Israel and securing the release of a kidnapped Israeli soldier.
At least 160 Palestinians have been killed in the offensive.
Some information for this report was provided by AFP, AP and Reuters.