German Chancellor Angela Merkel has expressed her frustration at Europe's inability - or unwillingness - to do more to help Syrians fleeing their country's civil war. She said it was "incomprehensible."
Mrs Merkel's comments came as dozens of refugees and migrants, including several young children, died when their boat capsized just moments after leaving the Turkish coast.
Video report by ITV News correspondent Juliet Bremner - some people may find the pictures in this report disturbing.
The Turkish foreign ministry says a Russian jet violated Turkish airspace on Friday, adding that "unwanted consequences will be Russia's responsibility".
Turkey has summoned the Russian envoy to condemn the alleged violation.
In a statement the ministry said the move was a clear sign Russia wanted issues between the two sides to escalate.
Tensions are high between the two countries after Turkey downed a Russian jet near the Syrian border in November 2015, which led to one of its pilots being killed.
Russia announced a string of economic sanctions against Turkey in response.
Up to 40 people, including five children, have drowned after a boat carrying refugees to the Greek island of Lesbos capsized.
Some 75 people were rescued after the 17-metre boat carrying at least 120 people sank off the coast of Ayvacik.
Many were hospitalised with hypothermia symptoms.
Rescue teams are continuing to search for survivors but the death toll is expected to rise.
A rocket understood to have been fired from Syria killed a female school worker and injured a female student at a Turkish school, officials have said.
The local governor's office said two other rockets understood to have been fired across Turkey's southern border had landed in an empty field next to the school in the province of Kilis.
The wounded student has been taken into surgery following the attack, a statement from the office confirmed.
Five people have been killed and 39 wounded after a Kurdish militant car bomb attack on a security force complex in south-east Turkey, local officials say.
Turkish security forces have arrested four people in connection with the suicide bombing in Istanbul in which 10 German tourists were killed, Turkish prime minister Ahmet Davutoglu has said.
Davutoglu said that the suicide bomber had entered Turkey as a migrant, adding that the perpetrator had not been monitored because they was not on a watch list.
Speaking to journalists, the Turkish prime minister said that six of those wounded in the blast remained in hospital, and vowed a more visible security presence in built up areas.
He said the bomber had not specifically targeted Germans.
All 10 people killed in Tuesday's suicide bombing in Istanbul were German, authorities have revealed.
A German foreign ministry spokeswoman made the announcement on Wednesday following the attack in Sultanahmet Square, near the Blue Mosque and Hagia Sophia, a popular tourist destination.
The bomber was a member of so-called Islamic State. It was thought he was born in 1988 and recently traveled to Turkey from Syria.
Turkish authorities have detained three Russian nationals suspected to have links to the so-called Islamic State following a suicide bomb attack in Istanbul on Tuesday.
Ten people were killed in the blast at Istanbul's historic Sultanahmet Square, an area popular with tourists.
The Russian Consulate in Turkey has confirmed the detentions, according to Russian media.
The blast in Istanbul was a strike on the Turkish people and its tourism with at least eight German tourists killed as they enjoyed a New Year holiday.
Authorities say they foiled an attack in November and another at New Year but the attack today shows that the country has become a target for terrorism and may face more in the future.
ITV News Correspondent Emma Murphy reports.
Turkish police detained nearly 60 suspected Islamic militants in raids across the country following a suicide bombing in Istanbul.
Some 21 of the 60 suspects were detained in the south-east city of Sanliurfa.
The raids come after at least 10 people were killed by a suicide bomber in Sultanahmet Square in Istanbul.
Turkey's prime minister said the suspected bomber was a foreign member of Islamic State.