The Anatolia news agency said on Sunday that the man was arrested in Hakkar, in southeastern Turkey, while he was about to cross into Iran using a false passport.

Police sources said the man had rented premises in an industrial district of Istanbul, where he prepared the explosives and installed them in four vehicles.

He was taken handcuffed and surrounded by police officers on Sunday morning to a warehouse in Istanbul, to show how the bombs were made and loaded onto the vehicles.

Sixty-one people, including four bombers, were killed in the attacks on November 15 and 20 which targeted two synagogues, the British consulate and the offices of the London-based HSBC bank.

So far 32 suspects have been held in connection with the attacks.

Turks suspected

Ankara says the attacks were carried out by Turks but there are suspicions of links to the al-Qaida network.

At least 25 people, including the British consul-general, were killed and over 300 injured in the two explosions on November 20.

British consul-general Roger Short was among the dead. He had reportedly arrived at his office just a minute before the explosion occurred.

The first explosion, caused by a car bomb, destroyed the first two floors of the HSBC building and caused extensive damage to the surrounding area.

The bank building is located opposite a busy shopping mall and next to the entrance of a city metro station. The explosion took place at 10:55 am (local time) when the business and shopping district were crowded.

The second bomb, targeting the British consulate in the central district of Beyoglu, was detonated minutes later, destroying at least six buildings. It also snapped electric lines and brought down telephone links in the crowded entertainment and shopping district.