ISTANBUL (AP) -- Turkish police on Saturday let off tear gas and pressurized water against groups of protesters trying to reach a main Istanbul square for a second day of anti-government demonstrations. Police also cracked down on hundreds of people trying to march toward Parliament in the capital, Ankara. The protests grew out of anger at heavy-handed police tactics to break up a peaceful sit-in to protect a park in Istanbul's main Taksim square on Friday. It turned into a wider protest against Prime Minister Recep Tayyip Erdogan, who is seen as becoming increasingly authoritarian, and spread to other Turkish cities. A human rights group said hundreds of people were injured in scuffles with police that lasted through the night. On Saturday, police clashed with several groups of youths trying to reach Taksim. Some threw stones at police. Some 500 people marched along the Bosporus Bridge from Asian shore of the city, toward Taksim, on the European side, but were met with pressurized water and tear gas that filled the air in a thick coat of smoke. Police detained a group of protesters who ran into a hotel to shelter from the gas, the private Dogan news agency reported. Ozturk Turkdogan, the head of the Turkish Human Rights Association, said hundreds of people in several cities were injured in the police crackdown and a few hundred people were arrested. The Dogan news agency said 81 demonstrators were detained in Istanbul. The protest was seen as a demonstration of the anger had already been building toward Turkish police who have been accused of using inordinate force to quash demonstrations and of firing tear gas too abundantly, including at this year's May Day rally. There is also resentment from mainly pro-secular circles toward the prime minister's Islamic-rooted government and toward Erdogan himself, who is known for his abrasive style. He is accused of adopting increasingly uncompromising stance and showing little tolerance of criticism. In a surprise move last week, the government quickly passed legislation curbing the sale and advertising of alcoholic drinks, alarming secularists. Many felt insulted when he defended the legislation by calling people who drink "alcoholics." "The use of (tear) gas at such proportions is unacceptable," Turkdogan told The Associated Press. "It is a danger to public health and as such is a crime. Unfortunately, there isn't a prosecutor brave enough to stand up to police." "The people are standing up against Erdogan who is trying to monopolize power and is meddling in all aspects of life," he said. Thousands marched through streets in several cities on Friday, calling on Erdogan to resign. Cars honked and residents banged on pots and pans in a show of solidarity with protesters. In the capital Ankara, thousands gathered at a small park and swelled into a popular shopping street. Many were seen drinking in the street protest of government restrictions on the sale and advertising of alcohol. Police broke up groups that tried to march toward the Parliament building, a few hundred meters (yards) away.