The site of a deadly blast outside a police station in an Istanbul suburb.<br/> <br />Turkish police on Tuesday said that the blast -- which killed at least one person -- was a suicide attack.<br/> <br />Istanbul's police chief spoke with reporters.<br/> <br />(SOUNDBITE) (Turkish) ISTANBUL POLICE CHIEF, HUSEYIN CAPKIN, SAYING:<br/> <br />"A suicide bomber blew himself up. The policeman working at the entrance was killed. Four security members including the station's police chief, a police captain and two police officers were wounded. The attacker blew himself up at the entrance of the police station."<br/> <br />The main domestic security threat in Turkey comes from the separatist Kurdistan Workers Party, or PKK, which is considered a 'terrorist' group by the United States, the European Union and Turkey.<br/> <br />But the PKK has focused its campaign on targets in the mainly Kurdish southeast.<br/> <br />Far-left groups and Islamist radicals have also carried out attacks in Istanbul in the past.
