ISTANBUL -- Two persons died and six others suffered injuries in a blast that rocked the district of Zeytinburun in this city on Monday, security sources said. The sources said the explosion occured while two persons were trying to set up a bomb, adding that the two men were suspected of being members of the outlawed rebel Kurdish organization, the Labor Party of Kurdistan (the PKK). Authorities have begun investigations into circumstances of the explosion.In the southern city of Gaziantep, 15 people died and many others were wounded in a blast of a vehicle boarding gas, the Anatolian news agency reported. "The blast was so powerful that it shook the ground under my feet," said a pedestrian who witnessed the fiery explosion.