Turkish police have broken up protests in Istanbul using tear gas and water cannon. Thousands gathered once again at Taksim Square to protest against the government. It is three weeks since the demonstrations began over a plan to build a shopping mall in nearby Gezi Park. Turkey's Prime Minister, Recep Tayyip Erdogan, has once again accused unnamed foreign plotters of whipping up the protests. Al Jazeera's Hashem Ahelbarra reports from Istanbul.