TUNIS (Reuters) - Tunisia Prime Minister Mohamed Ghannouchi announced his resignation on Sunday following a wave of street protests. Critics have accused Ghannouchi of being to close to the North African states former government, toppled in an uprising last month, and of failing to enact reforms. My resignation will provide a better atmosphere for the new era, he said, adding he wanted to prevent more victims in the countrys political unrest. Three people have been killed and several people wounded in clashes between security forces and demonstrators since Friday over Ghannouchis role in the interim government. My resignation is in the service of the country, he said on state TV. Meanwhile, three people were killed in clashes between Tunisian security forces and youths rioting in central Tunis on Saturday, an Interior Ministry official told Reuters. The official, who declined to be named, said another 12 had been injured in the clashes, which he said occurred after a riot orchestrated by loyalists of ousted President Zine al-Abidine Ben Ali. He said about 100 people had been arrested. Those who were arrested have admitted they were pushed by former Ben Ali officials, he said. Others said they were paid to do it. A Reuters witness had earlier seen Tunisian soldiers fire into the air and use tear-gas in an effort to disperse dozens of youths, many carrying sticks, who were breaking shop windows near Tuniss Barcelona Station.