ANKARA, Turkey (AP) – The Latest on Turkish explosion (all times local):

5:25 p.m.

NATO’s Secretary General Jens Stoltenberg has condemned the suicide bomb attack in Istanbul which killed at least four people.

Jens Stoltenberg said Saturday’s attack was “yet another terrorist outrage targeting innocent civilians and our ally Turkey.”

The attack injured 36 other people, including 12 foreign nationals.

A senior government official told the AP that authorities suspect that either Kurdish rebels or the Islamic State group is behind the attack.

Stoltenberg said: “There can be no justification for terrorism. NATO allies stand with Turkey, united in our determination to fight terrorism in all its forms.”

___

12:45 p.m.

Istanbul’s governor says one person who was severely wounded in the suicide attack in the city has died, raising the death toll to five. Vasip Sahin says the injured person died in hospital on Saturday following the explosion on Istanbul’s busiest pedestrian street.

___

12:10 p.m.

Istanbul’s governor says four people were killed in a suicide bomb attack in the city. The governor, Vasip Sahin, also says 20 people were injured injured, including three in serious condition.

11:50 a.m.

The private Dogan news agency says at least three people have been killed in the explosion on a busy pedestrian street in Istanbul. The agency said 10 people were injured and taken to hospitals. News reports say the explosion is believed to be caused by a suicide bomber.

___

11:30 a.m.

An explosion on Istanbul’s main pedestrian shopping street on Saturday has injured at least two people, Turkish media reports say. The Dogan news agency says the attack is believed to be a suicide bombing and injured at least five people.

The state-run Anadolu Agency reports that ambulances were responding to the explosion on Istiklal Street, which is also home to cafes, restaurants and foreign consulate buildings. Private NTV television said the explosion occurred outside a shopping mall.

The explosion comes as Turkey is on edge following two recent suicide bomb attacks in the capital, Ankara which were claimed by a Kurdish militant group, that is an off-shoot of the outlawed Kurdistan Workers’ Party, or PKK.