A bomb attached to an anti-NATO banner hanging from an overpass in Istanbul, Turkey, exploded Saturday, as police were securing the area.
There were no reports of injuries in the blast - the latest in Turkey before the start Monday of a two-day NATO summit to be attended by President Bush and more than 40 other world leaders.
Two explosions rocked Turkey Thursday - one outside the Ankara hotel where Mr. Bush is expected to stay, the other on an Istanbul bus, killing four people and injuring 14 others.
Earlier Saturday at least one person was killed and four others injured after a gas explosion at a hotel in a southern Turkish resort, Alanya. Police called the blast an accident.