Israeli tanks and troops ploughed deeper into Gaza yesterday, killing 11 Palestinians and occupying three former Jewish settlements in their biggest offensive since leaving the territory last year.

Helicopter gunships and artillery pounded the territory, as troops

moved further into both the northern and southern Gaza Strip, coming under heavy fire after a ninth consecutive night of air strikes and artillery assault.

The push effectively created a buffer zone in the north of the Palestinian territory and followed a second rocket attack on the

southern Israeli city of Ashkelon in as many nights that nevertheless caused no casualties.

Palestinian Prime Minister Ismail Haniya, whose Hamas-led government has been directly targeted in the offensive, slammed the assault as "collective punishment" on the Palestinians and demanded an international intervention.

Thursday's two-pronged onslaught, met by terrified Palestinians fleeing residential areas with babies and belongings, comes amid continued efforts to secure the release of a soldier abducted by Palestinian militants on June 25.

"There is no motivation to stay

there. We have no interest in returning. We have a simple interest to prevent the continuation of firing at our communities," vowed Infrastructure Minister Benjamin Ben-Eliezer.

In northern Gaza, ground forces, armoured vehicles and sappers advanced up to five kilometres (three miles) in a bid to expand a unilaterally declared interdiction zone aimed at preventing the incessant rocket attacks on Israel.

Further Israeli troops massed outside the towns of Beit Hanun and Beit Lahiya, in the deepest Israeli ground thrust since the 19-year-old Gilad Shalit was captured 11 days ago, sparking the worst Middle East crisisin months.

A 20-year-old civilian was killed by machine-gun fire from an Israeli tank in the Beit Lahiya, where Palestinian gunmen put up a heavy fight in a neighbourhood partially reoccupied by Israeli soldiers at dawn.

Two members of the armed wing of the governing Palestinian movement Hamas -- which claimed responsibility for Shalit's abduction -and a policeman were killed earlier in helicopter raids and tank shelling.

Trucks and infantry took over the remains of Dugit, Elei Sinai and Nissanit settlements, razed last year as part of Israel's historic pullout from the impoverished territory that had meant to draw the curtain on a 38-year occupation.