By Ercan Gurses

ANKARA (Reuters) - Turkish tanks and artillery have bombarded Islamic State positions in Syria and Iraq over the past 48 hours, killing almost 200 of its fighters in retaliation for a suicide bombing in Istanbul, Prime Minister Ahmet Davutoglu said on Thursday.

An Islamic State suicide bomber, who entered Turkey as a Syrian refugee, blew himself up among groups of tourists in the historic center of Istanbul on Tuesday, killing 10 Germans and seriously wounding several other foreigners.

Turkey, a NATO member and part of the U.S.-led coalition against Islamic State, would also carry out air strikes against the radical Sunni militants if necessary and would not yield until they were flushed from its borders, Davutoglu said.

"After the incident on Tuesday … close to 500 artillery and tank shells were fired on Daesh positions in Syria and Iraq," he told a conference of Turkish ambassadors in the capital Ankara, using an Arabic name for Islamic State.

"Close to 200 Daesh members including so-called regional leaders were neutralized in the last 48 hours. After this, every threat directed at Turkey will be punished in kind."

Davutoglu said the Turkish strikes had targeted Islamic State positions around Bashiqa in northern Iraq, where Ankara recently deployed a force protection unit to defend Turkish soldiers who are training an Iraqi militia in the fight against the Sunni radicals.

Cross-border strikes into Syria targeted an area around the rebel-held town of Marea, 20 km (12 miles) from the Turkish border and near the edge of a "safe zone" Turkey wants to establish in northern Syria to keep Islamic State at bay.

"Our ground strikes on these positions are continuing and if necessary our air force will come into play," Davutoglu told the conference.

Interior Minister Efkan Ala said earlier seven people had been detained in connection with the Istanbul bombing. Turkey has rounded up hundreds of suspected Islamic State members in its efforts to crack down on the group's domestic networks.

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Russia's foreign ministry said one of three Russian men among those arrested after the Istanbul bombing was suspected of having links to Islamic State and that such extremists "feel comfortable" in Turkey. It named him as Aidar Suleimanov, born in 1984.

Russian news agencies said he was suspected of helping send new recruits from Russia to the militant group. It was not clear if he was thought to have been directly involved in the Istanbul bombing.

WAR ON TWO FRONTS

Turkey was long a reluctant partner in the U.S.-led coalition fighting Islamic State, refusing a frontline military role and arguing that only the ouster of President Bashar al-Assad - not just bombing the jihadists - could bring peace in Syria, an argument it maintains.

But it has faced a series of deadly attacks by the radical Sunni militant group over the past six months, including a suicide bombing in the border town of Suruc last July and a double bombing in Ankara in October which killed 100 people, the worst attack of its kind on Turkish soil.

Ankara launched what it called a "synchronized war on terror" in July which has mostly involved air strikes and a ground campaign against Kurdistan Workers Party (PKK) militants in its southeast, but also included allowing its Incirlik air base to be used by coalition countries to bomb Islamic State.

Its armed forces have been stretched as they fight on two fronts, with the violence in the largely Kurdish southeast, where the PKK has fought a three-decade insurgency for greater Kurdish autonomy, at its worst since the 1990s.

Kurdish militants attacked a police station in the southeast with a truck bomb overnight, killing six people including a baby and two toddlers in one of the biggest strikes since a two-year ceasefire collapsed in July, security officials said.

Although Turkey initially carried out a limited number of air strikes against Islamic State in Syria as part of the U.S.-led effort, its warplanes have not flown in Syrian air space since Turkey shot down a Russian fighter jet in late November, triggering a diplomatic row with Moscow.

Davutoglu on Wednesday again accused Russia of protecting Islamic State in Syria by bombing opposition forces fighting the group rather than Islamic State itself and said Russia's entry into the Syrian war was obstructing Turkish air strikes.

"They should either destroy Daesh themselves or allow us to do it," he told a news conference on Wednesday.

(Additional reporting by Daren Butler, Ayla Jean Yackley and Melih Aslan in Istanbul, Dmitry Solovyov in Moscow; Writing by Nick Tattersall, editing by Peter Millership)