Kurdish militants appear to have been behind a car bombing that killed 11 people in central Istanbul on Tuesday, a Turkish presidential spokesman says, while a second bomb killed four people in the largely Kurdish southeast today.

At least one person die and 13 are injured in a car bomb blast near a police headquarters in the Turkish city of Gaziantep, officials say.

The suicide bomber who killed four people in Istanbul's main shopping street belonged to so-called Islamic State (IS), the interior minister says.