Turkey said Wednesday it had arrested five people in connection with a deadly suicide bombing that ripped through the historic heart of Istanbul, killing 10 German tourists and raising alarm over security in the country.

Ankara has said that Tuesday's attack was carried out by a 28-year-old Syrian who belonged to the Islamic State (IS) group and had recently entered Turkey from Syria.

Turkish security forces over the last days also rounded up 74 suspected IS members across the country, state media said, but it was not clear if any were directly connected to the Istanbul bombing.

One person was arrested on Tuesday evening in connection with the bloodshed, Interior Minister Efkan Ala said on Wednesday, without explaining the suspect's role in the strike.

Wednesday Prime Minister Ahmet Davutoglu announced the arrest of four additional suspects.

"Four more people involved in the attack have been arrested today," Davutoglu told a news conference in Istanbul, adding that the Islamic State (IS) group's links to the attack had been confirmed.

The German foreign ministry in Berlin said Wednesday that 10 of those killed in the attack were German, without specifying if they accounted for all the victims.

But de Maiziere said there was "no indication" the attack specifically targeted Germans, saying there was no need to cancel travel plans.
"It was an attack against humanity," he said. "I see no reason to refrain from trips to Turkey."

But the German foreign ministry has advised its nationals to keep away from large groups in public places and tourist attractions in Istanbul.

German tourism giant TUI said customers who had booked trips to Istanbul can switch destination without paying a penalty.
Turkey has been hit by a string of deadly attacks blamed on jihadists over the last year, including a double suicide bombing in October in Ankara that killed more than 100 people.

But Tuesday's bombing was the first time in recent memory tourists had been targeted in the heart of Istanbul.

The bomber, identified as Nabil Fadli, detonated his charge in Sultanahmet Square, home to Turkey's most visited historic sites including the Ottoman-era Blue Mosque and Hagia Sophia church.

The explosion went off by the Obelisk of Theodosius, a monument from ancient Egypt, one of the city's most iconic landmarks.

The Sabah daily said the bomber had entered Turkey as a refugee from Syria on January 5.

Source: AFP