Right-wing Israeli cabinet member Natan Sharansky resigned on Monday in protest at Prime Minister Ariel Sharon’s planned withdrawal from Gaza, a sign of widening internal rifts ahead of the pullout.Underlining growing tensions on the Palestinian side too, Islamic militants dismissed an order by President Mahmoud Abbas’s government to stop carrying weapons on Gaza streets. Sharansky, whose writings on democracy have impressed US President George Bush, quit as diaspora affairs minister, complaining that Sharon’s formula for ‘‘disengaging’’ unilaterally from conflict with the Palestinians could invite more violence. ‘‘In my view, the disengagement plan is a tragic mistake that will exacerbate the conflict with the Palestinians, increase terrorism, and dim the prospects of forging a genuine peace,’’ he said in an open resignation letter. It was the latest of several ideological walkouts from the government. Many Israelis fear that resistance by Jewish settlers due to be evacuated from some occupied territories could turn violent. — Reuters