Turkey's prime minister says he cannot be 100 percent sure that the al-Qaida terrorist network was involved in a week of suicide bombings that left more than 55 people dead in Istanbul.
Istanbul is still coming to terms with the effects of a week of terror. The city's British community gathered in a sandstone church overlooking Istanbul's famous Golden Horn waterway to pray for the victims of the attacks, including Britain's consul general.
A day earlier, at the funerals of two policemen killed in the attacks, Prime Minister Recep Tayyip Erdogan said he felt shame that the four suicide bombers were Turkish nationals. But he told British television that, although he is convinced the perpetrators had international connections, he cannot be certain that al-Qaida was behind the attacks.
A group that says it is part of al-Qaida and a Turkish radical-Muslim organization that said it acted in conjunction with al-Qaida have both claimed responsibility for the four attacks.
Mr. Erdogan also called for help from the international community in tracking down the masterminds of the suicide attacks and said the bombings must not derail Turkey's hopes of joining the European Union.
Turkish commentators and foreign diplomats say Mr. Erdogan's ruling Justice and Development Party will have to move carefully in the weeks and months ahead. They say his party, which has Islamic roots, could lose support among secular voters and come into conflict with the powerful military and security establishment if it fails to stamp out religious extremism.
But if the crackdown is too tough, they add, that could compromise the civil liberties reforms his government has undertaken to meet EU membership requirements.
The Turkish newspapers Radikal and Milliyet report that Turkey's National Security Council has ordered improvements in coordination between the intelligence services and police in monitoring the activities of Turkish Islamic extremists. The reports quote unnamed security sources as saying that a lack of such coordination allowed the militants time to plan and carry out last week's attacks.
The authorities are reported to be concentrating their investigation on Turkish Islamic radicals who fought in such places as Afghanistan, Bosnia, and Chechnya during the past decade and may have established contact with militants from other countries. The Interior Ministry says at least 1,000 Turks fall into that category and that many of them are in Turkey and could have linked up with home-grown extremist groups.