Ankara - Police experts on Monday were searching for clues as to who was behind a bomb attack in Istanbul Sunday night that left 16 people dead and 154 injured, the Anadolu news agency reported.

A first small bomb which had been placed in a rubbish bin on a crowded pedestrian street in the suburb of Gungoren on the European side of Istanbul exploded at around 9:45 pm (1645 GMT) and was followed by a much larger blast around 10 to 12 minutes later and around 50 metres down the street, Istanbul Governor Muammer Guler told reporters at the scene of the blast.

Witnesses told NTV television that many people had gone to inspect the scene of the first blast when the second bomb exploded.

Television footage showed wounded people running away from scene as well as damaged cars and shops in the area near the blast on Menderes street, a popular summer strolling area.

Early media reports suggested that Kurdish separatists may have organized the attack, but Milliyet newspaper quoted an intelligence officer in Ankara who said the Kurdish Workers' Party (PKK) had denied any responsibility.

Radical Islamists have carried out bomb attacks in Istanbul in the past, including suicide bombing on synagogues, the HSBC Bank and the British Consulate in 2003 which left dozens dead.

Prime Minister Recep Tayyip Erdogan cancelled his official programme for Monday in order to rush to Istanbul and President Abdullah Gul condemned the attacks.

"No aims can be achieved with violence, killing innocent people and terrorism," Gul said. "These attacks show how inhumane and terrible the perpetrators are." (dpa)