Prime Minister Recep Tayyip Erdogan was due back in Turkey on Thursday to face thousands of angry demonstrators calling for him to quit, as violence flared between the protesters and his supporters.

Away for four days on an official trip, Erdogan has defied the protesters who are against the conservative policies of his Islamic-rooted AKP party, dismissing them as "extremists" and saying everything would calm down before he returned.

The White House praised Turkey's government Tuesday for apologizing for the use of force against protesters in the biggest mass demonstrations of Prime Minister Recep Tayyip Erdogan's decade in power.

Deputy Turkish Prime Minister Bulent Arinc said earlier the government had "learnt its lesson" and regretted using security forces against people with "rightful demands."

Turkish premier Recep Tayyip Erdogan left Morocco for Algeria on Tuesday, the second leg of a North African tour, as the worst political crisis of his 10 years in power showed no sign of abating.

After arriving on Monday at the head of a senior ministerial delegation and accompanied by a large number of businessmen, he and Moroccan counterpart Abdelilah Benkirane signed a joint political declaration on developing strategic ties, official Moroccan media said.

Turkey must conduct a far-reaching, independent probe on its security forces' treatment of anti-government protesters who have taken to the streets across the country, the U.N.'s human rights office said Tuesday.

"We're concerned about reports of excessive use of force by law enforcement officers against protestors in Turkey," said Cecile Pouilly, spokeswoman for the U.N. high commissioner for human rights.

Turkish Prime Minister Recep Tayyip Erdogan arrived in Rabat on Monday at the start of a tour of the Maghreb region, an Agence France Presse photographer reported, as unprecedented anti-government protests swept Turkey.

Erdogan, who is accompanied by several ministers and a large delegation of businessmen, landed at Rabat airport at around 1400 GMT.

A young demonstrator was killed in Istanbul by a car that rammed into a crowd during a wave of protests against Turkey's government as Prime Minister Recep Tayyip Erdogan announced on Monday that the situation is "calming down."

"The situation in my country is now calming down... On my return from this visit, the problems will be solved," Erdogan told a news conference in Rabat during an official visit to Morocco.

Thousands of people were on Sunday occupying Istanbul's Taksim Square, the epicenter of the worst demonstrations in a decade against Turkey's Islamist-rooted government which have seen almost 1,700 people detained and scores wounded.

A sea of protesters from across Turkey's political spectrum were camping out in the iconic square, chanting "Government, Resign!" and "Istanbul is ours, Taksim is ours!" as they celebrated after the police pulled out of the site on Saturday.

Turkish police on Saturday began pulling out of Istanbul's iconic Taksim Square, the scene of a second day of violent clashes between protesters and police over a controversial development project.

Thousands of demonstrators flooded the site as police lifted the barricades around Taksim Excursion Park and began withdrawing from the square, an Agence France Presse reporter saw.

Turkish Prime Minister Recep Tayyip Erdogan on Saturday visited his country's volatile border with war-torn Syria, urging citizens to keep welcoming refugees after deadly bombings early this month fueled local resentment.

"We should help our brothers in need. They are here because they believe in us and they have confidence in us," he told residents of Reyhanli, a small south-eastern border town where 51 people were killed and about 100 injured in twin car bombings on May 11.

Turkish Prime Minister Recep Tayyip Erdogan will sue opposition leader Kemal Kilicdaroglu after he compared him to Syria's embattled president over deadly bombings near the border, media reported Saturday.

"We will not allow anyone to call the prime minister of the Turkish Republic a 'murderer'," Erdogan was quoted as saying by the Vatan newspaper during a visit to Washington.