A Turkish court on Wednesday remanded in custody pending trial two more suspects over a suicide bombing blamed on the Islamic State (IS) group that killed 10 German tourists in Istanbul last week, reports said.

A court in Istanbul placed the suspects -- who were detained in southeastern city of Sanliurfa on Saturday -- under arrest on charges of "premeditated murder and membership in a terror group", the Anatolia news agency reported.

German and Turkish police on Wednesday announced major coordinated raids against a criminal trafficking network that used unseaworthy ships to send more than 1,700 refugees to Europe.

The joint operation was a major strike against international organized crime fueling the record migrant wave to Europe, police chiefs from both countries told a press conference at Potsdam outside Berlin.

The blanket curfew in Silopi lasted 36 days as clashes raged between the Turkish army and Kurdish militants. Finally it was lifted, allowing residents to come to terms with the scale of the destruction in their hometown.

The curfew in Silopi, a town of some 80,000 in the Kurdish-dominated Sirnak province of southeastern Turkey, was one of several imposed as the army wages a relentless campaign to crush Kurdistan Workers Party (PKK) militants.

Greece's President Prokopis Pavlopoulos on Monday accused Turkish border authorities of facilitating people smuggling by turning a blind eye to the trafficking of thousands of migrants to Europe.

"I have a strong fear that Turkish smugglers have the support of the authorities, in particular, border authorities who act like they have seen nothing," he told German daily Sueddeutsche Zeitung.

Turkish prosecutors on Monday launched an investigation into the head of Turkey's main opposition party for calling President Recep Tayyip Erdogan a "tinpot dictator", adding to concerns over freedom of expression in the country.

Kemal Kilicdaroglu was speaking out against the detention of Turkish academics last week over a petition condemning the military crackdown in the Kurdish-dominated southeast, just days after Erdogan threatened the signatories.

A Turkish court on Sunday charged ten people over the suicide bombing in the heart of Istanbul's tourist district that killed 10 Germans, media reported.

The ten, who were charged with belonging to a terrorist organization, were remanded in custody, the Dogan news agency said.

The European Union on Saturday condemned as "extremely worrying" Turkey's arrest of academics who signed a petition criticizing a military crackdown in the Kurdish-dominated southeast.

"The steps taken against the Turkish academics who signed a declaration regarding events in the southeast of Turkey are an extremely worrying development," an EU spokesperson on foreign affairs said in a statement.

The General Security announced on Saturday the arrest of a Lebanese national on terrorism charges.

It said that M.M. was arrested for belonging to the Islamic State extremist group.

Turkish authorities on Thursday discovered the bodies of seven would-be migrants to Greece on western Turkish beaches, the official Anatolia news agency said.

Police opened an inquiry into the drownings, discovered barely a week after the bodies of 36 migrants, including several children, were found after boats spiriting them across the Aegean Sea to EU member Greece sank.

Turkish ground forces pounded Islamic State jihadists in Iraq and Syria after a suicide attack blamed on the group killed 10 German tourists, Prime Minister Ahmet Davutoglu said on Thursday.

"After the heinous attack in Istanbul, our armed forces hit in the last 48 hours some 500 positions of Daesh in Syria and Iraq with artillery and tank fire," Davutoglu told Turkish ambassadors in Ankara, using an Arabic acronym for IS.