Three people suffered serious injuries during the Wednesday raids, according to Palestinian medical sources.
Israeli army officials declined to confirm the missile attacks, but said troops were scouring the region for pockets of resistance that continued to launch homemade Qassam rockets on Israel's Negev towns.
Israel's military radio also reported that a number of tanks and armoured vehicles had been deployed to the entrance of Jabalya - the largest refugee camp in Gaza.
Aljazeera's correspondent in Gaza, Hiba Akila, reported that five Palestinians were injured when troops, backed by gunships, forced entry into Jabalya and Bait Lahia, opening fire randomly. The injured are still in hospital.
Akila said statistics show that Qassam rocket attacks always increase during Israeli incursions.
Aljazeera has also received a video from al-Nasir Salah al-Din Brigades - the military wing of the Palestinian Popular Resistance Committees - in which fighters promised to target the Israeli town of Sderot in response to the latest raid on Bait Hanun.
The video showed masked men with home-made rockets.
Air raids and rockets
The two raids come just a month after tanks and infantry stormed in and around Bait Hanun, also in northern Gaza, and razed orchards and farmland they said could be used for cover by resistance fighters.
Medical sources say eight civilians
have suffered shrapnel wounds
Israel says the town of Sderot is now targeted daily by inaccurate Qassam rockets.
Therefore, Israeli troops have had to expand their incursion westward into the Jabalya refugee camp area, Israeli officials say.
Meanwhile, the Hamas resistance group on Tuesday issued a video carried by al-Arabiya satellite television in which it swore to keep raining rockets on Sderot unless Israel ended its 37-year occupation of Gaza.
Israeli Prime Minister Ariel Sharon aims to evacuate Jewish colonies from Gaza next year under his "disengagement plan", but has vowed to crush resistance first to prevent them from claiming victory.
Meanwhile, Israeli forces have also arrested 12 Palestinian activists in the West Bank towns of Nablus, Qalqilya and Hebron, Aljazeera reported.
Occupation forces also searched four houses in Azun Itma village east of Qalqilya after raiding and imposing a curfew on it.
The arrests come after Israeli authorities banned the Palestinian police and security apparatuses from carrying weapons in Palestinian West Bank cities and towns.
Tel Aviv has threatened the Palestinian Security Apparatus that troops will raid every security headquarters if it learns it contains weapons.