ISTANBUL, Jan. 12 -- At least 10 people have been killed and 15 others wounded in an explosion that hit Istanbul's historic Sultanahmet Square, a tourist hub, on Tuesday, the Istanbul governor's office said.

The explosion took place at around 10:15 local time (0815 GMT) at the square, and the investigation is going on to determine the cause and its perpetrators.

A suicide bomber is suspected to be behind the deadly attack.

"All I heard was a loud noise and then we saw smoke over there ... I didn't move anywhere, I stayed here and waited till the police came. Soon after ambulances arrived and now the police cordoned off the area," a shop owner nearby told Xinhua.

Turkey has suffered from Islamic State (IS) attacks. In July, 2015, a bombing attack in the border town of Suruc in southeastern Turkey left 34 pro-Kurdish and left-wing activists killed. In October, a huge explosion in the capital Ankara killed 86 and injured 186. Both were blamed on the IS.

While battling the IS, Turkey is also cracking down the home-grown Kurdish Workers' Party (PKK), a terrorist group that has also been blacklisted by the United States and the European Union.

The Turkish military said Sunday that a total of 448 PKK militants had been killed in counter-terrorism operations in southeastern Turkey, where tensions have been running high, since mid-December.