ANKARA, Jan. 12 (Xinhua) -- The deadly suicide attack in the heart of Istanbul on Tuesday that killed 11 people has exposed the vulnerability of Turkey to serious security challenges in a turbulent region where terrorism is on the rise.
This is a blowback from the ongoing criminal activities by terrorist groups operating in Turkey's troubled neighbors in the southeast, namely Syria and Iraq, Mehmet Seyfettin Erol, the professor of international relations told Xinhua.
He said he fears the fallout from the neighboring countries may worsen further.
If the terror is capable of staging an attack in the heart of business capital in Turkey, then we should be really worried, Erol added.
Turkish government Spokesman and Deputy Prime Minister Numan Kurtulmus told reporters that 11 people have been killed, while 15 others were injured with two being in critical conditions in a suicide attack on Tuesday.
Turkish Prime Minister Ahmet Davutoglu revealed that the bomber was a member of Islamic State (IS) from Syrian origin and added that all those who lost their lives in the blast were foreigners.
The attack happened in Turkey's largest city Istanbul's historic Sultanahmet Square, a major tourist attraction in the downtown area of the old city that is home to landmark structures like the Blue Mosque and Hagia Sophia.
Officials said most of those killed were German nationals.
According to Ercan Tastekin, the head of Ankara-based Research Center for Security Strategies, the location was especially picked up by the terror group to send a message that Turkey is not a safe country to visit.
He also underlined that another goal was to hurt tourism industry.
Istanbul is a city that generates one third of tourism revenue for Turkey that hosted 36 million tourists in 2015.
Turkey earned some 30 billion U.S. dollars from tourists in 2014. It is estimated that the revenue would drop to 28 billion dollars in 2015.
Terror groups like IS and Al-Qaida target foreigners in order not to lose their sympathizers in Turkey, Tastekin commented.
According to a survey released by the Pew Research Center in November found out that eight percent of Turks have said they have a favorable opinion of the IS while 73 percent expressed disdain for the radical group.
Turkey has suffered from a series of deadly attacks in recent years. On 6 Jan. 2015, a woman carried out a suicide bombing attack on a police station in Istanbul's Sultanahmet, leaving an officer dead.
A bombing attack in the border town of Suruc in southeastern Turkey in July 2015 left 34 pro-Kurdish and left-wing activists killed. In October 2015, twin suicide bombings hit the capital city Ankara, claiming a total of 103 lives.
All three were blamed on the IS.
Turkey also faces a bloody campaign by Kurdish militants from the banned Kurdish Workers' Party (PKK) which is listed as a terrorist organization by Turkey, the United States and the European Union.
Turkish opposition political parties put the spotlight on ruling Justice and Development Party (AKP) government, accusing it of failing to prevent the deadly suicide attack in Istanbul.
This government is not capable of governing Turkey, the main opposition Republican People's Party (CHP) leader Kemal Kilicdaroglu told lawmakers in Turkish Parliament on Tuesday.
He blamed the government for not taking precautions in a place that is considered to be the heart of tourism in Istanbul.
The Nationalist Movement Party (MHP) leader Devlet Bahceli also highlighted the failure in intelligence and security services.
He pointed out that the acceptance of Syrian refugees without a plan and allowing them to move around the country have posed social, economic and security risks to Turkey.
Armagan Kuloglu, a security analyst and former military commander, said that when Turkey allowed millions of Syrians to come to Turkey, the terrorist IS elements penetrated Turkish borders.
These crossings should have been checked more properly in order to stop terrorists coming into the country, he underlined.
Turkey is home to 2.5 millions refugees, most of whom are Syrians who fled the conflict in their home country.
However, Deputy Prime Minister Kurtulmus dismissed that there was any security and intelligence vulnerability in Istanbul's Sultanahmet district.
He recalled that police successfully detained two suspected IS militants on Dec. 30 last year on suspicion of plotting suicide attacks in Ankara on New Year's Eve.