Turkish police say they have arrested a man suspected of ordering one of four suicide bomb attacks that shook the nation's commercial capital, Istanbul, in recent days. The suspect, whom police declined to identify, was detained as he tried to cross the border into neighboring Iran.

Istanbul's deputy police chief, Halil Yilmaz, said the man, who was arrested Tuesday, had helped plan the suicide bomb attack against the Beth Israel Synagogue, and ordered its execution on November 15.

Mr. Yilmaz said the suspect was taken to the scene of the blast early Saturday, and ordered to describe in full detail how the attack was carried out.

Turkey's private NTV television carried pictures of the man, who was bearded, handcuffed and appearing to be in his 20s. He was wearing a bulletproof vest, and was surrounded by police.

The arrest came as police kept up an investigation into the four suicide bomb attacks. The first two were mounted simultaneously against two synagogues on November 15. The second set of bombings took place five days later, targeting the British consulate and a London-based bank.

All the bombings were in Istanbul. At least 61 people were killed and more than 700 others injured when explosives-laden pick-up trucks slammed into the targets. The Al-Qaida terrorist network has claimed responsibility for all four attacks.

Turkey's interior minister, Abdul Kadir Aksu, said the investigation had not yet established any foreign connection to the bombings.

The suicide bombers themselves were all identified as ethnic Kurds from Turkey's predominantly Kurdish southeast provinces. All were believed to have links with Hezbollah, a militant Islamic group that has no connection with its Middle East namesake, but which Turkish authorities say has been covertly supported by Iran.

Police say 20 people have been charged in the bombings, so far. U.S. and Israeli security officials are reportedly helping with the investigation.