A suicide bombing has left at least five people dead in a busy shopping area popular with tourists and locals in Istanbul.

The governor of Istanbul Province, Vasip Sahin, initially said four people had been killed and 20 people injured in the attack in İstiklal Avenue, also known as Istiklal Street.

But the death toll rose under an hour later as another victim died of their injuries in hospital.

Three Israelis were among the wounded, the country’s foreign ministry said, but nationalities of the other victims were not immediately confirmed.

CCTV footage of the explosion showed shoppers milling around on the street when the bomb was detonated next to a group of people standing on the pavement.

People could be seen lying motionless on the floor as survivors ran for cover.

The wide pedestrianised avenue is one of the most famous streets in Istanbul, lined with boutiques, art galleries, theatres, cafes and foreign consulates, leading to Galatasaray Square.

Local residents said the area hits its peak on weekends afternoon and evenings and that 11am local time (9am GMT), when the blast hit, would have been comparatively quiet.

Helicopters and ambulances were seen converging on the scene as rescue efforts continued.

The explosion comes as Turks are on the edge following a string of attacks across the country.

At least 37 people were killed and 125 others injured in a suicide bombing in central Ankara on 13 March.

Another 28 people were left dead by another bombing in the same area of the Turkish capital in February. Both attacks have been claimed by a splinter Kurdish militant group known as the Kurdistan Freedom Hawks (TAK).

The Islamic State (Isis) group and the Kurdistan Workers Party (PKK) have also engaged in violence on Turkish soil in recent months.

Both factions have committed atrocities in Turkey at an increasing rate over the past year as Turkey continues military operations in Kurdish areas in the south-east and the Syrian war rages over the border.

It is also battling the PKK in its southeast, where a two-and-a-half-year ceasefire collapsed last July, prompting the worst violence since the 1990s.

Turkey sees the unrest in its largely Kurdish southeast as deeply linked to events in northern Syria, where the Kurdish YPG militia has seized territory as it fights both ISIL and rebels battling President Bashar al-Assad.

ISIL has carried out at least four bomb attacks on Turkey since June 2015, including a suicide bombing which killed 10 German tourists in central Istanbul in January.

The Foreign Office has been warning of a high threat from terrorism, warning that attacks from a range of Islamist and Kurdish groups could be indiscriminate and target areas frequented by foreigners.

Growing speculation that the blast was another terror attack aimed at hitting Turkey's tourist industry and liberal social scene could not be confirmed and there was no immediate claim of responsibility.

Germany closed its embassy in Ankara and a consulate and German school in Istanbul last week because of a warning over an imminent attack. 

Both the Istanbul school and consulate are situated near Istiklal Street but it was unclear if the threat was linked to Saturday's attack.

This is a developing story*

Courtesy Aljazeera The Independent