ISTANBUL, Turkey, March 19 (UPI) -- A suicide bomb attack near a crowded shopping area of central Istanbul killed at least four people, including two Americans and two Israelis, and injured 36 more.
The incident marks the fourth major blast in the country in recent months.
Both the U.S. and Israeli governments said at least two of their citizens each are among the dead. A spokesman for the U.S. National Security Council condemned the attacks and said American officials are working with Turkish allies to investigate the incident.
Israeli Prime Minister Binyamin Netanyahu said his government was investigating whether the Israeli citizens were the bomber's deliberate targets. The dead were members of a 14-person tour group on vacation in Istanbul.
The explosion occurred just before 11a.m. local time Saturday near a government building in the area, reports confirm. No known terror group such as the Islamic State or Kurdish militants has claimed responsibility for the blast.
At least 12 of those wounded were foreign nationals, the country's Health Minister Mehmet Muezzinoglu said during a telecast. Seven of those injured are reportedly in critical condition.
Some media outlets were reporting there were five deaths as a result of the bombing Saturday, not four.
The blast comes less than a week after 37 people were killed in a suicide car bombing in the Turkish capital of Ankara. About 125 were injured in the bus station explosion, later claimed by the Kurdistan Freedom Hawks (TAK) -- an affiliated branch of the Kurdish PKK.
In February, TAK admitted responsibility for a similar attack killing 28 in the capital city.
The latest suicide attack comes as a flurry of similar explosions which have occurred in the country in the last six months.