Revd Turgay Ucal from All Saints Moda Church on the Asian side of the city has spoken to Premier about his concerns for safety in Istanbul.
Officials in Turkey have said an Islamic State suicide bomber detonated a bomb in Sultanahmet which killed ten people.
They report at least nine of the victims were German, while 15 other people were hurt in the blast, which struck an area popular with tourists.
Revd Ucal said: "Istanbul is a huge city. When we look around the world, it seems quite safe and life is going on. [There are now] two million Syrians in Turkey. There are terrorist groups also entering the inside of the country with all these different groups. As city people, we are just questioning. I'm questioning 'is it safe, is it not safe?"
Prime minister Ahmet Davutoglu blamed IS for the explosion, adding Turkey is determined to battle the group until it no longer "remains a threat".
Mr Davutoglu has spoken on the phone with German chancellor Angela Merkel to express his condolences, the country's state-run news agency reports.
He also held a security meeting with officials including the country's interior minister, immediately after the explosion.
President, Recep Tayyip Erdogan, said: "I strongly condemn the terror incident that occurred in Istanbul, at the Sultanahmet Square, and which has been assessed as being an attack by a Syria-rooted suicide bomber."
Angela Merkel said the victims were part of a German travel group and, speaking at a news conference in Berlin, she condemned the attack: "Today Istanbul was hit, Paris has been hit, Tunisia has been hit, Ankara has been hit before. International terrorism is once again showing its cruel and inhuman face today."
The blast struck a park 30-yards from the historic Blue Mosque and it could be heard across a wide area.
Numan Kurtulmus, Turkey's deputy prime minister, said the bomber was a 28-year-old Syrian national whose "connections" were being investigated.
Mr Kurtulmus also said two of the wounded were in a serious condition.
Turkey's Dogan news agency said one person from Norway and a Peruvian were among those hurt, and Seoul's Foreign Ministry said a South Korean had a finger injury.
The Norwegian Foreign Ministry told Norway's news agency NTB the Norwegian tourist was slightly hurt and was receiving treatment in a nearby hospital.
Meanwhile, German and Danish citizens are being warned by their respective governments to stay away from crowds outside tourist spots in Istanbul.
Turkey last year agreed to play a more active role in the US-led battle against IS and opened its' bases to US aircraft to launch air raids on the extremist group in Syria.
The nation has carried out a small number of strikes itself, while it's also tightened security along a 560-mile border with Syria, to try and stop the flow of militants.
The Sultanahmet area was sealed off by police in the event of another explosion, and a police helicopter was dispatched.
Sultanahmet is Istanbul's top tourist spot, boasting the Topkapi Palace and the former Byzantine church of Haghia Sophia, which is now a museum.
Authorities responded to the explosion in Sultanahmet by imposing a news blackout, which stopped media organisations from reporting any details of the investigation, or showing images of the dead or hurt.
Two major bombing attacks in Turkey last year were both blamed on Islamic State.
A suicide attack in the town of Suruc, near the Syrian border, in July, claimed more than 30 lives.
More than 100 people were killed in Turkey's deadliest attack when two suicide bombs exploded as people gathered in October for a peace rally outside Ankara's main railway station.