Turkish police have warned Western embassies and businesses to be on alert for further terrorist attacks during the Christmas holiday season.
In a memo that was circulated to Western businesses and embassies and leaked to the Turkish and Western media, Turkish police warned that a group of terrorists has recently infiltrated the country from an unnamed neighboring state.
The memo says the group is preparing to mount attacks against Western targets. The police say the plan is to be a third wave of attacks, to follow up the recent suicide bombings aimed at Western and Jewish targets in Istanbul.
Security measures at likely terrorist targets, including major airports, government buildings and embassies, have been tightened since last month's wave of attacks. Turkish police and Western officials say they are certain that the al-Qaida terrorist network planned the car and truck bombings of two synagogues, the British consulate, and a British-based bank.
Turkish police are keeping up the hunt for likely suspects in those bombings, all four of which were carried out by Turkish citizens from the predominantly Kurdish southeast region.
Several key figures involved in the bombing, who were detained during the past month, have said they received orders to attack Western targets in Turkey from al-Qaida leader Osama bin Laden, during various trips to Afghanistan.
Acting on information from those detainees, Istanbul police have arrested another suspect, Mehmet Kus, and found 12 bags of chemical fertilizer at his home in Istanbul. Police said it was the same substance used in the November blasts, which claimed nearly 60 lives.