On the day Israelis marked the third anniversary of the capture of soldier Gilad Shalit a senior Palestinian politician has been released from detention in Tel Aviv.Aziz Dweik, the Hamas speaker of the Palestinian parliament, was freed after Israeli prosecutors failed to persuade a military court to extend his prison term. He was rounded up with dozens of other Palestinians after gunmen seized Shalit. Supporters of the young soldier blocked a crossing into Gaza in protest against his continued captivity. The group, which included his father, prevented supplies getting into the territory for a time. Negotiations earlier this year on a possible prisoner exchange involving Shalit and large numbers of Palestinians hit an impasse. Relatives of some being Palestinains held in Israel staged a counter protest on the Gaza side of the border.