Police and protesters who are angered at the Israeli withdrawal from the Gaza strip have been locked in a violent stand-off as security services try to stop the demonstrators advance. The ultra-nationalists are trying to push ahead with the march to the Gaza settlements, which has been officially banned, and tried to break through a police cordon. They want to to disrupt the pullout process from the Jewish settlements which is scheduled for mid-August. Police say some 6000 demonstrators had massed at Kfar Maimon though organisers say the number was more than twice that. They started in Netivot and now want to make the Kissufim Crossing in order to reach their final destination Gush Katif. Israeli Prime Minister Ariel Sharon’s disengagement plan has angered ultra-nationalists who say Israel is giving up a biblical birthright and rewarding the Palestinian uprising. With at least 20 arrests, today’s was the biggest showdown so far and could be a preview of clashes to come once Israel begins evacuating some of the settlements in the West Bank and all of those in Gaza.