Turkish Prime Minister Recep Tayyip Erdogan has said his government will go ahead with controversial plans to overhaul a small park in central Istanbul, despite mass protests against the redevelopment in Taksim square.

Speaking to reporters in Tunis after a meeting with his Tunisian counterpart on Thursday, Erdogan said some groups were manipulating what had started as an environmental protest, and that a number of foreigners had been arrested.

Turkish assets weakened on after Erdogan made the announcement.

The main Istanbul share index fell 4.24 percent by 1234 GMT, while the lira weakened to 1.8914 against the dollar following Erdogan's comments.

The protests in Turkey were sparked early June by the police break-up of a sit-in to prevent the demolition of a park in central Istanbul.

The demonstration spiralled into rallies by thousands denouncing what they say is the government's increasingly authoritarian form of governing and its meddling in people's lifestyles.

Al Jazeera's Anita McNaught, reporting from Ankara, said Erdogan also stressed on the amount of vandalism caused by protesters on some infrastructure, saying that it "was scarecely in the name of environmentalism."

On the alleged excessive use of force against those protesting, Erdogan did not make an outright apology, and said that "the neccessary words" of regret had already been said by his deputy prime minister.