Turkish authorities say a double bomb attack in Istanbul has killed at least 15 people and wounded 150 others.

The bombs went off several minutes apart Sunday evening on a shopping street in a residential district of Gungoren in western Istanbul.

Officials say the first bomb caused a small blast in a telephone booth, drawing a crowd to the site before the second and more powerful device exploded. Both bombs were placed in trash cans.

Turkish President Abdullah Gul condemned the attack and described its perpetrators as ruthless and savage terrorists. Authorities are investigating who was behind the bombings.

Several groups have carried out bomb attacks in Istanbul in the past, including Kurdish separatists, far-left activists and Islamists.

Some information for this report was provided by AFP, AP and Reuters.