Three men on Friday went on trial at a Turkish court facing life imprisonment over the murder and attempted rape of a 20-year-old female student that unleashed a wave of anger over violence against women in the country.

Ozgecan Aslan was murdered in the southern region of Mersin in February while returning home from a shopping trip on a minibus, in a crime that sparked street protests and Internet campaigns.

Turkey on Thursday said it was taking measures to limit the flow of Syrian refugees onto its territory after an influx of thousands more over the last days due to fighting between Kurds and jihadists.

Under an "open-door" policy championed by President Recep Tayyip Erdogan, Turkey has taken in 1.8 million Syrian refugees since the conflict in Syria erupted in 2011.

A Turkish policeman who tear-gassed a female protester at close range in one of the most iconic moments of 2013 anti-government protests has been ordered by a court to plant 600 trees, media reported Thursday.

The tear-gassing of Ceyda Sungur was captured in dramatic images and she became known as the "lady in red" around the world due to the color of the dress she wore.

Turkish President Recep Tayyip Erdogan on Thursday called for the swift formation of a new coalition government, ending almost four days of unusual silence after legislative polls seen as a blow to his authority.

Erdogan's comments added weight to expectations of a coalition government in Turkey after the ruling Justice and Development Party (AKP) he co-founded lost its majority in Sunday's dramatic polls.

More than 2,000 refugees crossed from Syria into Turkey on Wednesday, fleeing clashes pitting Kurdish fighters against the Islamic State (IS) group, a Turkish official said.

"Of those displaced, 686 are Iraqi nationals who first fled their country and then were forced to flee Syria," a Turkish official told AFP.

Turkey's ruling party will talk to the opposition on forming a coalition government after it lost its overall parliamentary majority in legislative elections, Prime Minister Ahmet Davutoglu said Wednesday.

However he warned that the Justice and Development Party (AKP) would consider every option, including early elections, if the discussions fail.

Turkish authorities have detained 17 people over clashes between rival Kurdish groups that left four people dead and inflamed tensions in Turkey's main Kurdish city days after legislative elections, officials said Wednesday.

The violence broke out in Diyarbakir on Tuesday when Aytac Baran, the leader of a charity linked to the Kurdish Islamist political party Huda Par, was shot dead, prompting a gunfight that left three more people dead and 11 injured.

Turkey's usually highly loquacious President Recep Tayyip Erdogan has made no spoken comment since his party lost its parliamentary majority in weekend elections, prompting intrigue and mockery in opposition media.

Erdogan's silence since the elections has surprised many in Turkey who are used to seeing him deliver several speeches a day in rallies or television programs, lashing out at opponents.

Three people were killed Tuesday, including the leader of an Islamist charity, in clashes between rival Kurdish groups in Diyarbakir, the interior ministry said, adding to tensions in Turkey's largest Kurdish-populated city days after legislative elections.   

Aytac Baran, the leader of the Ihya-Der charity group, was shot dead by unknown gunmen outside his home in Diyarbakir, prompting a gunfight that left two others dead. 

A French mother took the government to court on Tuesday for failing to stop her teenage son from leaving the country to join jihadists in Syria.

The boy, identified only as "B", was 16 when he left with three others from the town of Nice in southern France on December 27, 2013, giving no warning to his family.