At least four people have been killed and 36 others injured in Taksim suicide bombing on Saturday.
At least one Iranian and one Israeli citizen were among the dead from a suicide bombing in a central Istanbul shopping district, said a Turkish official, speaking to Reuters agency.
Turkey's Health Minister, Mehmet Müezzinoğlu, said that 36 people were wounded, including 12 foreigners.
The foreign victims were from Israel, Ireland, Island, Germany and United Emirates.
Seven of the injured are in serious condition.
Turkish Deputy Prime Minister Numan Kurtulmuş said that his country will remain committed to fighting terrorism.
Kurtulmuş spoke after a suicide bombing in Taksim which left five people dead, including the bomber.
“They are trying to impose a treacherous plan, but no matter what they do, it will not work. This nation will never surrender to their traps," Kurtulmuş told reporters.
“No matter what they do, we will never get used to terror. We will never become inured to terrorism," he noted.
Kurtulmuş stressed that Turkey will never take a step back in its fight against terrorism. “The nation will live in peace until doomsday, making the eternal brotherhood never-ending," he added.
Foreign Minister Mevlut Çavuşoğlu said Turkey will continue to fight terrorism resolutely “Our fight against terrorism will continue as in the past, in a determined way in every field, inside and outside," Çavuşoğlu said.
The foreign minister called on Western countries to act together with Turkey in the struggle against terror.
The bomber is said to be a man in his 30s. After examining fingerprints from remains, police will start an investigation.
Chief prosecutor Hadi Salihoğlu arrived on the scene and personally inspected the investigation.
Reports said that five prosecutors will investigate the suicide bombing.
Saturday's attack followed another suicide bombing which targeted a major transportation hub in the Turkish capital, Ankara, on March 13 and left 35 civilians killed.
The Kurdistan Freedom Hawks (TAK), a Kurdistan Workers' Party (PKK)-affiliated group, claimed responsibility for Sunday's suicide bombing.
Sunday's explosion took place less than a month after a car bomb attack in Ankara on February 17 left 29 dead. The TAK also claimed responsibility for this attack.
Turkey has been the target of terrorist organizations, particularly the PKK and affiliated groups such the Democratic Union Party (PYD) and its armed wing, the People's Protection Units (YPG), The Kurdistan Freedom Hawks (TAK) along with Daesh, which killed 11 people at Istanbul's Sultanahmet Square in January.
Also, previously in 2015, Ankara witnessed the deadliest attack in modern Turkish history, in which 102 people were killed on October 10 when two suicide bombers detonated themselves in a rally near the capital's main train station.
Turkish officials frequently reiterate the country's determination to fight against terrorist groups.
Most recently, Turkish President Recep Tayyip Erdoğan previously said instead of capitulating to terrorism, Turkey would defeat the parties trying to bring Turkey down with brutal attacks.