'Run' - heroic Istanbul guide screamed at tourists after spotting suicide bomber pulling out explosives pin
* Attack killed 10 German tourists
* Bomber thought to have registered in Istanbul a week ago
* German minister says Germans not deliberate target
* One detained in investigation into attack
A suicide bomber who killed himself and 10 German tourists in Istanbul's historic heart had registered with Turkish immigration authorities but was not on any list of known militant suspects, Turkey's interior minister said on Wednesday.
The bomber, an Islamic State member thought to have come recently from Syria, blew himself up on Tuesday in Sultanahmet square near the Blue Mosque and Hagia Sophia, major tourist sites in one of the world's most visited cities.
Asked about a report in the Turkish media that the bomber had registered at an immigration office in Istanbul a week ago, Interior Minister Efkan Ala confirmed that the man's fingerprints were on record with the Turkish authorities.
"Your assessment that his fingerprints were taken and there is a record of him is correct. But he was not on the wanted individuals list. And neither is he on the target individuals list sent to us by other countries," Ala told a joint news conference with his German counterpart Thomas de Maiziere.
Turkey's Haberturk newspaper published what it said was a CCTV image of the bomber, identified in some local media reports as Saudi-born Nabil Fadli, at an immigration office in Istanbul on Jan. 5.
It said he was identified by a sample of a finger taken from the blast site.
Deputy Prime Minister Numan Kurtulmus said on Tuesday the bomber had been identified from body parts at the scene, was born in 1988, and was thought to have been living in Syria, from where he was believed to have recently entered Turkey.
Ten Germans were killed in the bombing, a spokeswoman for the German foreign ministry said, raising the death toll among Germans from 9 previously.
Turkey, which like Germany is a member of the U.S.-led coalition against Islamic State in Syria and Iraq, has become a target for the radical Sunni militants.
It was hit by two major bombings last year blamed on the group, in the largely Kurdish town of Suruc near the Syrian border and in the capital Ankara, the latter killing more than 100 people at a pro-Kurdish rally in the worst attack of its kind on Turkish soil.
The Istanbul attack, targeting groups of tourists as they wandered around the square, appeared to mark a change in Islamic State's tactics against Turkey.
"This incident is a bit different. In previous attacks, it was Turks who crossed into Syria to fight Kurds and then crossed back to attack Kurdish targets," said Aaron Stein, senior fellow at Atlantic Council's Rafik Hariri Center for the Middle East.
It's different in terms of intentions and in terms of its targets," he told Reuters.
GERMANS NOT DELIBERATE TARGET
Foreign tourists and Turks paid their respects at the site early on Wednesday. Scarves with the Bayern Munich football club emblem were left along with carnations and roses at the scene, before Turkish police sealed off the area.
De Maiziere said there were no indications Germans had been deliberately targeted and that he saw no reason for people to change travel plans to Turkey. He said Germany stood resolutely by Turkey's side in the fight against terrorism.
"If the terrorists aimed to disturb, destroy or jeopardise cooperation between partners, they achieved the opposite. Germany and Turkey are becoming even closer," he said.
"Based on what we know from the investigation so far, there are no indications that the attack was explicitly targeting Germans so there cannot be a link with our contribution to the fight against international terrorism," he said.
The guide of the German group was quoted by Turkey's Hurriyet newspaper as saying she had yelled "run" after seeing the bomber, who was standing among the tourists, pull a pin on his explosives, enabling some of them to get away.
Ala said nine other Germans were wounded in the blast, two of them still in a serious condition in hospital, along with one Norwegian and one Peruvian. He vowed to work closely with Germany in investigating the attack.
One person was detained late on Tuesday as part of the investigation into the blast, Ala said, but gave no details. He defended Turkey's record in fighting Islamic State, saying 200 suspects had been detained just a week before the blast.
He said Turkey had detained 3,318 people over suspected links to Islamic State and other radical groups since Syria's conflict began, 847 of whom, most of them foreigners, had subsequently been arrested.
Turkish media reports said on Wednesday the authorities had detained three Russian nationals as part of the crackdown on Islamic State, but it was not immediately clear whether the move was part of the investigation into the Istanbul attack, for which there has been no claim of responsibility.
Russia's Consulate General in the Mediterranean city of Antalya said three Russians had been detained over suspected connection to Islamic State, Russian state news agency RIA said.
Police seized documents and CDs in a search of the premises where they were staying, Turkey's Dogan News Agency said.