A bomb exploded in the centre of Turkey's capital city during rush hour this morning, killing two people and wounding others, according to local media reports.
Istanbul's governor has said 11 people were killed in the explosion, and 36 were wounded.
A Turkish police bus was the target of the bomb attack, which took place near a university and a number of tourist sites in the densely populated Vezneciler district in central Istanbul.
A parked car packed with explosives was detonated by remote control as a police personnel bus passed by, according to reports.
There has been no claim of responsibility for the attack. Kurdish militants, Islamic State and radical leftists have all staged attacks in Turkey recently, and Istanbul was the target of an attack in March and in January this year.