Suicide bomber kills four in Istanbul's historic Beyoglu district

A suicide bombing has rocked a major shopping street in Istanbul, killing four people and wounding 36 others just six days after a deadly attack in Ankara, Turkish authorities said.

The explosion on Saturday morning ripped through Istiklal avenue near the local governor’s office in Beyoglu - an area popular for nightlife and shopping.

"This is a suicide attack, a terrorist attack," Istanbul governor Vasip Sahin said, adding that the bomber was also killed.

The dead were reported by Turkish authorities to be three Israelis and one Iranian.

Turkish media said three Israelis and one Iranian were killed, while two of the Israelis were also named by Washington as US citizens. 

"The United States condemns in the strongest possible terms today's terrorist attack in Istanbul" National Security Council spokesman Ned Price said in a statement.

Health Minister Mehmet Muezzinoglu said 36 people were injured, seven seriously, and that 12 foreigners were among the casualties. 

Saturday's blast was the sixth attack of its kind in Turkey since July.

Amateur video footage appeared to show the scene shortly after the blast:

Local Turkish media reported that the explosion may have been the result of a prematurely detonated suicide bomb. A CNN Turk reporter was quoted by Hurriyet as saying the suicide attacker had been on his way to the target when his bomb detonated outside a restaurant.

Turkish authorities enforced a media blackout on the area following the blast, as has become standard following attacks in the country.

Istiklal avenue is a hub for tourists and secular Turks, and is home to numerous shops, bars and clubs.

Turkey has recently been struck by a number of bomb attacks by both the Islamic State group and Kurdish militant groups.

A bomb attack in the capital Ankara last week which killed 37 people was claimed by the Kurdistan Freedom Falcons (TAK), a splinter group from the the Kurdistan Workers' Party (PKK).

In January, a suicide bomber believed to be affiliated to IS struck Istanbul's tourist-heavy Sultanahmet district killing 10 people.

Turkey's tourist industry has been heavily damaged by repeated bombings as well as the rise in violence in the country's southeast.