ISTANBUL (Reuters) - Turkish Interior Minister Efkan Ala has resigned, Prime Minister Binali Yildirim said on Wednesday, following a string of bombings that prompted public criticism and concerns about intelligence failures before last month's failed coup.


The prime minister did not give a reason for the resignation in his brief statement broadcast on Turkish television channels.


But Turkey has faced a series of attacks blamed on Islamic State and Kurdish militants, and President Tayyip Erdogan told Reuters in July that there had been clear intelligence failures in preventing last month's failed coup attempt.


The Interior Ministry portfolio has been filled by Labor Minister Suleyman Soylu, the prime minister said.


Soylu said a day after the coup bid that it was clear "America is behind it", though Erdogan's spokesman later said he had spoken "in the heat of the moment".


A senior official told Reuters that some of the appointments Ala had made while in post had raised concerns, as well as "his inability to meet expectations in some areas, primarily security."

The interior minister has a high profile role in a nation seeking to stop foreigners crossing the southeastern frontier to join Islamic State in Syria. The minister is also on the front line of efforts to prevent militants infiltrating back into Turkey.

In addition, Turkey has been battling an insurgency by the Kurdish militant group PKK that is seeking autonomy in the southeast of the country. The group has launched a series of attacks since a ceasefire broke down last year.

The minister has been at the center of a campaign to root out sympathizers of the July 15 coup that sought to topple Erdogan and his government.

"Erdogan expects a much more effective fight against Fethullah Gulen organization," the senior official said, adding that "Soylu is one of the names Erdogan trusts the most."

The Turkish authorities have removed from public duties about 80,000 people suspected of having sympathies with the plotters and with a U.S.-based cleric Fethullah Gulen, whom officials accuse of masterminding the putsch.

Earlier on Wednesday, the outgoing interior minister had released new figures about the number of people arrested in the Turkey's crackdown against Islamic State militants.

Ala said 865 people had been arrested since the start of 2016 alone, and more than half of those were foreigners.

The new labor minister was named as Mehmet Muezzinoglu, a deputy chairman of Erdogan's AK Party.

(Reporting Asli Kandemir, Nick Tattersall and Orhan Coskun; Writing by Edmund Blair; Editing by Ralph Boulton)