A bomb blast today killed at least five people on an Istanbul bus - only days before the Turkish city hosts a NATO summit attended by US President George W Bush, British Prime Minister Tony Blair and other world leaders.
It was the second explosion in Turkey today - the first being near an Ankara hotel where Mr Bush is due to stay at the weekend.
The Istanbul blast, in the residential Fatih district, about five miles away from the summit area, also injured about 20 people. Two policemen were among three people injured in the Ankara explosion.
The Turkish capital's Police Chief Ercument Yilmaz said his officers were injured when they approached a package containing the explosives to verify an anonymous tip that a bomb had been placed nearby.
The bomb exploded neat the entrance of the hotel, shattering windows of nearby buildings.
President Bush is scheduled to arrive in Ankara on Saturday night for talks with Prime Minister Recep Tayyip Erdogan and President Ahmet Necdet Sezer.
Militant Islamic, Kurdish and left wing groups have carried out past attacks in Turkey, and scores of people believed to be linked to such groups have been arrested in security sweeps in recent weeks.
Concerns about security have grown in Turkey since last November, when four suicide truck bombings killed more than 60 people
- including the British consul
- in Istanbul attacks on two synagogues, the British consulate and a London-based bank.
AP