Turkey PM Erdogan demands 'immediate end' to protests

"I call for an immediate end to the demonstrations, which have lost their democratic credentials and turned into vandalism," he told a yelling crowd of supporters at an Istanbul airport.

Thousands of supporters greeted Turkish Prime Minister Recep Tayyip Erdogan upon his return from an overseas trip Thursday, in the largest public boost for the embattled leader since mass protests against his rule erupted a week ago.

Waving Turkish flags and shouting "We will die for you, Erdogan", more than 3,000 supporters of the premier's Justice and Development Party (AKP) flocked to the Istanbul airport where he was due to arrive after a four-day trip to North Africa, an AFP reporter saw.

It was the AKP's first public show of strength after keeping largely silent during seven days of violent anti-government demonstrations across the country, in what could prove a decisive moment in the crisis.

Some 15 miles (25 kilometres) away, thousands of whistle-blowing protesters were gathered in Istanbul's iconic Taksim Square, the epicentre of the protest movement, chanting: "Erdogan, Resign!"

Erdogan has so far responded with defiance to the biggest challenge of his decade-long rule, further enraging protesters on Thursday by vowing to press ahead with a planned park redevelopment in Istanbul that sparked the protests.

The nationwide unrest, fuelled by anger against what protesters see as Erdogan's growing authoritarianism, has claimed a third life with the death of a policeman, media said.

Doctors have reported thousands of injured in the past week as police tried to quell the rallies in major cities with tear gas, pepper spray and water cannon.

Speaking in Tunis on Thursday, Erdogan reiterated his claims that extremists and foreign agitators were to blame for the violence, and refused again to cancel plans to raze Istanbul's Gezi Park, whose conservation fight lit the flame of the protests.

"Among the protesters, there are extremists, some of them implicated in terrorism," including some who were in Taksim Square where the trouble broke out last week, he told reporters.

Seven foreigners implicated in the unrest have been arrested, Erdogan said, without specifying what part they had played in the violence.

Later in Ankara, Interior Minister Muammer Guler said the foreigners detained were two French, two Iranians, a Greek, a German and an American, and that two had been released.

Erdogan's uncompromising stance on the park project did not go down well with protesters in Istanbul, who said they were determined to win the battle.

"We are angry. He doesn't listen," said biologist Senay Durmus, 25, vowing that she would protest in Taksim "every day after work until we win".

But many stressed the widespread displays of outrage went beyond Gezi Park.

"This started with some trees. But I think it's about freedom," said 32-year-old Ali Ihsan Canimoglu, goggles wrapped around his wrist to protect his eyes in case of a tear gas attack.

-- First police fatality --

A Turkish policeman died in hospital Wednesday hours after being injured in a fall while chasing anti-government protesters in the southern city of Adana, the private NTV news channel said.

His death marked the first police fatality in seven days of clashes, with two young male protesters killed earlier.

Opposition to Erdogan is intense, but the 59-year-old has won three elections in a row and gained almost 50 percent of votes in 2011, having presided over strong economic growth in recent years.

CNN-Turk television reported on Thursday that several hundred people attacked a group of 25 youths who staged an anti-government protest in the Black Sea port of Rize, Erdogan's native town.

Erdogan has said he could "mobilise a million supporters of my party" if he had to.

"AKP supporters are like sheep. If Erdogan says go fight, they will fight. If he says stay, they will stay," said 24-year-old protester Ezgi Ozbilgin in Gezi Park.

-- 'Not a second-class democracy' --

The national doctors' union has said that more than 4,300 have been injured in recent days, 47 of them seriously.

Erdogan's critics accuse him of forcing conservative Islamic values on Turkey, a mainly Muslim but staunchly secular nation.

Turkey, while acknowledging some police excesses, has hit back at criticism of its handling of the crisis, a Turkish foreign ministry source told AFP on Wednesday.

The diplomat, speaking on condition of anonymity, said Foreign Minister Ahmet Davutoglu had told US Secretary of State John Kerry in a phone call Tuesday: "Turkey is not a second-class democracy."

The US State Department later denied suggestions this was Washington's view of its NATO ally, a key strategic partner in the region, but said it had concerns "about instances of police brutality".

A top US official urged Turkish leaders Thursday to refrain from "unhelpful comments" after Erdogan accused "terrorists" of stoking the protests.

"We remain supportive... of peaceful protest and of freedom of speech that individuals are asserting in the country," State Department spokeswoman Jen Psaki told reporters.

But she added that Washington "would encourage any official there to refrain from unhelpful rhetoric and unhelpful comments that will not help calm the actions... happening in Turkey."

Other Western allies of Turkey -- a country that straddles East and West and has long aspired to join the European Union -- have also voiced concern over the violence.