The Israeli government moved on two fronts on Wednesday to secure next month's withdrawal from the Gaza Strip by closing the territory's borders to rightwing Jewish activists and launching an offensive against Palestinian militants attempting to disrupt the pullout.

In the wake of a suicide bombing that killed four people in the Israeli city of Netanya on Wednesday, Ariel Sharon, prime minister, ordered the military to wage a “relentless attack” against Islamic Jihad, the Palestinian organisation that claimed responsibility for the first such attack in five months.