Turkey says it has established a link to Afghanistan in the weekend suicide bombings of two Istanbul synagogues.
The attacks on Saturday killed 25 people and injured 300. An Arabic newspaper said Osama bin Laden's al-Qaeda network, which operated in Afghanistan until the militant Islamist Taliban administration was overthrown by US forces in 2001, had claimed responsibility for the attacks.
Turkish Foreign Minister Mr Abdullah Gul was asked by reporters whether the attacks, which shook world markets, were linked to al-Qaeda.
"It has emerged that there is a link [in the Istanbul suicide attacks] with an organisation in Afghanistan in terms of belief and understanding," Mr Gul told reporters. He gave no details.
"The emerging evidence demonstrates that the security services have been very successful in their work," he said. "A trail has been found and relationships have emerged."
He did not say whether Turkish security services, who are being helped by Israeli authorities, were moving towards any arrests.