A large explosion was heard Tuesday morning in Istanbul’s central Sultanahmet Square – a major tourist attraction and hub in the Turkish city.

Turkish security forces and paramedics were quickly deployed to the square. 

According to a statement issued by the Istanbul Governor’s Office, at least 10 people were killed in the blast and another 15 wounded. The statement confirms that some of those among the injured were German and Norwegian tourists. 

It appears the explosion was caused by a bomb planted in the garden of the Sultan Ahmet (Blue) Mosque. The mosque is one of the symbols of Istanbul and a major tourist attraction.   

Some witnesses claimed a suicide bomber detonated the device. These reports have not been confirmed by Turkish authorities. 

Witnesses speaking to the CNNTürk station reported hearing a loud blast and a huge flame was seen during the blast which took place at around 10:15 a.m Turkish time. 

The blast occurred in the heart of Istanbul’s tourist district, close to the Sultanahmet tram stop and Dikilitas, the Obelisk of Theodosius. 

Police have closed off the roads surrounding the area in fear of a second bomb. 

The Israeli Foreign Ministry is currently investigating as to whether any Israelis were in the area during the time of the explosion.

Turkish Prime Minister Ahmet Davutoglu convened an emergency meeting in Ankara following the blast. A senior official told Reuters that “terrorist links” were suspected, but had made no further comment.  

Later on Tuesday, Turkish President Recep Tayyip Erdogan said the attack was caused by a suicide bomber of Syrian origin. 

“I strongly condemn the terror attack which was carried out by a suicide bomber of Syrian origin,” Erdogan said in a speech in Turkish capital Ankara in his first reaction to the blast.

“Unfortunately… there are fatalities, including locals and foreigners,” Erdogan lamented. “This incident showed again we have to stand together in the face of terror.”

“Turkey’s determined position will not change. We don’t make any difference between the names or abbreviations (of terror groups).”

“The first target of all the terror groups active in this region is Turkey. Because Turkey fights them all with the same determination.”