"A detailed and sensitive investigation and analysis of the event is ongoing," Ala said.
But just as officials tried to reassure nervous tourists, a new blast rocked Turkey -- an attack on a police headquarters in the Cinar district of Turkey's southeastern province of Diyarbakir, Turkey's semiofficial Anadolu Agency reported, citing local officials.
At least five people were killed and 39 were wounded in that blast.
A car laden with explosives
The Diyarbakir Governor's Office issued a statement saying the PKK -- the Kurdistan Workers' Party -- was a prime suspect in the bombing. The PKK has waged a long and deadly insurgency for decades against the Turkish government in an effort to gain greater rights and autonomy for Kurds.
The Anadolu Agency report said the terrorists detonated a car laden with explosives and simultaneously launched an attack on the district office with gunfire.
There has been no claim of responsibility for the attacks.
Attack comes two days after Istanbul bombing
The attack in Diyarbakir comes on the heels of the suicide bombing Tuesday in Istanbul.
Turkish authorities have blamed the Istanbul attack on the terrorist group ISIS
-- although Prime Minister Ahmet Davutoglu said Wednesday, somewhat mysteriously, that ISIS had not been the primary actor.
"An ISIS connection has been identified but ISIS is a pawn, an intermediary organization, a subcontractor," Davutoglu said. "We are working to reveal the real actors behind this terror organization."
PM: Turkey 'will never take a step back'
Tuesday's suicide bombing in Sultanahmet Square was a strike at the heart of Turkey's culture and its multibillion-dollar tourist industry.
And Davutoglu promised Wednesday to make a determined effort to repel the threat.
"We will continue our fight against terrorism with the same resolve and will never take a step back," he said, according to Anadolu Agency.
But he added that Istanbul had "become a city of hope today in the rings of fire in the region, to the people of the Middle East, Balkans and Caucasus."
True to his promise to fight back, Davutoglu's government issued a statement saying it had launched a fierce military assault on ISIS.
"After it was determined that ISIS conducted this lowly attack, our Armed Forces, upon our instructions, hit ISIS locations in Syria and Iraq with approximately 500 artillery and tanks via ground in the last 48 hours since the day of the attack," the statement read.
"ISIS locations and hide outs were hit from Bashiqa in Iraq and along our Syrian border with all our capabilities. In the last 48 hours, nearly 200 ISIS members, who were all individually identified, among them: so-called regional leaders, were neutralized."
Security sweeps across seven provinces
As if to underscore the government's resolve, Turkey detained 68 suspected terrorists in sweeps across seven provinces, Anadolu Agency reported Wednesday.
That included three Russians who were staying at a house in Antalya, according to an account also reported by Russia's state-run Sputnik news.
One of the three is suspected of being linked to ISIS, a spokesperson for the Russian Foreign Ministry told CNN. Russian officials say his name is Aidar Suleimanov and he was born in 1984.
Suleimanov was wanted by police in the Tartarstan region of Russia in connection with ISIS-related terror activities, according to the ministry spokesperson, who said his details had been circulated to Interpol.
Another 21 people held in Sanliurfa were "preparing for attacks in Turkey," according to Anadolu Agency. And 16 people -- 15 of them Syrian -- were detained in Ankara for allegedly starting to scout out buildings there.
One of those caught in the security sweep is being held in connection with the Istanbul blast, Ala said on Wednesday. That brings the total number of people detained so far in connection with the Istanbul bombing to eight.