Istanbul - Barbaros Yesim has written his blood type, A-positive, on his right forearm.

On Tuesday in Taksim Square, where protests against the government raged for a fifth day, the 22-year-old demonstrator said the scribble in blue ink was a precaution against more police violence in clashes that have resulted in two deaths and more than 1,500 injuries since Friday.

Despite a police pullback and a qualified official apology Tuesday, Turkey's largest public demonstrations in years showed no sign of abating. Like the writing on Yesim's arm, the protests that have spread to cities across the country are a forceful symbol of the depth of public anger and mistrust toward Prime Minister Recep Tayyip Erdogan.

"This is a scream for attention on the part of millions of people who feel they are being ignored," said Bulent Aliriza, a Turkey specialist at the Center for Strategic and International Studies, who lives in Washington and Ankara, the Turkish capital. "It's an accumulation of resentments about the increasingly authoritarian style of Erdogan."

In a decade at the helm, Erdogan has become the most powerful Turkish leader in generations, overseeing a remarkable economic transformation of his nation and making Turkey a much more assertive player in international affairs and a key U.S. ally.

But Erdogan has lost a bit of swagger at home since he visited Washington last month and failed in his very public efforts to persuade President Barack Obama to send more military aid to Syrian opposition forces. Widespread condemnation of violence by government security forces in Taksim Square stands to chasten Erdogan further, analysts said.

"There is now a huge question mark over Erdogan's government," Aliriza said.

Erdogan's human rights record has been widely criticized, and critics complain that he is trying to introduce deeply conservative Islamic ideals into Turkey's fiercely secular society. Although his popularity in opinion polls remains high, critics say Erdogan has grown increasingly divisive, heavy-handed and intolerant of dissenting voices.

In a move that some Turks viewed as an arrogant dismissal of the protests - but others saw as a shrewd way to calm them - Erdogan left Monday for a three-day trip to Morocco, Tunisia and Algeria. He had denounced the demonstrators as "looters" and "extremists."

But in his absence, Deputy Prime Minister Bulent Arinc gave a limited apology for the government's response to the protests and offered to meet with the demonstrators.

"The excessive violence that was used in the first instance against those who were behaving with respect for the environment is wrong and unfair. I apologize to those citizens," he said at a Tuesday news conference in Ankara, according to the Reuters news agency. "But I don't think we owe an apology to those who have caused damage in the streets."

The protests began last week as a peaceful demonstration against Erdogan's plans to build an Ottoman-style military barracks and shopping mall in one of central Istanbul's most popular parks.

As crowds built around Taksim Square throughout Tuesday, Atilla Yesilada, an analyst at Global Source Partners in Istanbul, said conciliatory rhetoric was positive but insufficient to stop the protests.

"Saying 'I understand where you are coming from' is meaningless if you are still hitting the guy with a baseball bat," he said. "There's a mile-long gap between the rhetoric and the action."

When the protests erupted Friday, Erdogan responded by sending riot police to crush them.

"He is acting like a dictator," said Devrim Bozcuk, 17, a high school student who joined the protesters in Taksim Square on Tuesday.

U.S. Secretary of State John Kerry cited the "excessive use of force" by the Turkish police and urged "full restraint."

After bloody confrontations over the weekend, police pulled back and allowed protesters to continue occupying the park.

The demonstrations have broken the relative calm that Turkey enjoyed while other countries in the region were engulfed by the Arab Spring uprisings. And they have rattled Turkey's financial markets, potentially jeopardizing the growth that Erdogan has overseen. The stock exchange fell more than 10 percent Monday, before gaining 4.9 percent Tuesday, and the Turkish lira lost value against the dollar and the euro.

"As long as the economy was holding up, people were willing to look the other way at the lack of freedoms," Aliriza said. "If the investment dries up, people will begin to question the success of Erdogan's government."

Under Erdogan, Turkey's per-capita gross domestic product has more than tripled. Erdogan constantly touts his "2023 Vision" of roads, bridges, housing and other massive development projects he vows to complete before the centennial of Turkey's founding. His government is also trying to land the 2020 Summer Olympics in Istanbul, and the city is full of banners promoting the bid.

Aliriza said a thuggish government response to peaceful protests will probably scare off the foreign investment that Turkey needs to fuel its economy and fund Erdogan's grand plans. "For now, Erdogan's OK," Aliriza said. "But if the economy heads south, then we are going to see a real threat to this government."

Since Erdogan was elected in 2003, his government has jailed hundreds of military officers, students and lawyers, as well as more journalists than any other nation. Rights groups, and the U.S. State Department, have said that his critics are reluctant to speak out against him for fear of retribution.

Owners of major media companies are often hesitant to allow negative coverage of Erdogan. On Monday, the Agence France-Presse news service reported, 3,000 people rallied outside the Istanbul headquarters of a big media group, complaining that mainstream television stations showed cooking or wildlife shows over the weekend rather than covering the protests.

"He doesn't respond or react to criticism, except to punish, to fire people or put them in jail," said Osman Faruk Logoglu, a former Turkish ambassador to the United States who is a member of parliament from the opposition Republican People's Party, known as CHP for its Turkish initials.

Erdogan has also proposed changes to the constitution that could allow him to remain in power for another 10 years.

"He thinks that he is empowered by God and the only truth is what he thinks and what he says; he is intoxicated by power," said Tugrul Turkes, a leader of the opposition National Action Party, known as MHP for its Turkish initials.

Erdogan, an Islamist former mayor of Istanbul, has deeply divided the nation along class and economic lines, drawing his strongest support from rural areas and his most vocal critics from Turkey's urban elite and growing middle class.

Many Turks also believe that Erdogan is trying to undermine the clear separation between state and religion that has defined modern Turkey since its founding in 1923 by Mustafa Kemal Ataturk. Most recently, Erdogan's government proposed new limits on the sale of alcoholic drinks.

"The prime minister cannot tell me what to drink at what time of the day," said Melis Ugur, 37, who works for a cellphone company in Istanbul and has taken part in the protests.

Ugur said Erdogan has done little to improve women's rights. In 2004, he proposed criminalizing adultery.

"The people don't think they are listened to, that they are valued. We are so fed up with the prime minister," she said. "We feel humiliated as women. He is always humiliating people who do not vote for him."

On Tuesday evening, Taksim Square and Gezi Park, the site of the proposed development that sparked the protests, were again filled with demonstrators. Some had set up a makeshift medical clinic in front of a Starbucks, offering milk, water and food, as well as bandages, iodine and other medical supplies.

Protesters formed a human chain to stockpile water bottles. Others sold painter's masks for about a dollar to protect against potential tear-gas attacks. But except for a few overturned vehicles, it was almost impossible to distinguish the protest from a festival. Women danced and music played while vendors sold kebabs and snacks.

Authorities were nowhere to be seen.