One person was killed and at least 12 others were injured when a bomb exploded at an airport in the southern Philippines today, authorities said. An improvised explosive device (IED) caused the blast near the arrivals area of Zamboanga airport, regional police commander chief superintendent Edwin Corvera said. The mayor of Zamboanga, Celso Lobregat, put the toll at one dead and at least 12 injured, one of them seriously. "Initial investigation suggests the one who carried the bomb was killed in the explosion," he said in a ABS-CBN television interview. "We do not want to speculate at this time (on) who the bombers are." Mr Lobregat said the blast occurred just after a plane from Manila had landed and as passengers were leaving the terminal. The explosion was just outside the terminal, he said. Zamboanga is one of the main cities on Mindanao island, where a Muslim separatist insurgency has left more than 150,000 people dead since 1978. Zamboanga is also one of the strongholds of the al Qa'eda-linked Abu Sayyaf, a small group of Islamic militants on the US government's list of terrorist organizations. The Abu Sayyaf is blamed for the country's worst terrorist attacks, including a ferry bombing that killed over 100 people in Manila Bay in 2004. It has also conducted a series of kidnappings of both locals and foreigners in the southern Philippines. In one of their highest-profile kidnappings, the group seized three American and 17 local tourists from a beach resort on Palawan island southwest of Manila in 2001. They beheaded one of the Americans, and another was killed during a rescue attempt a year after the kidnapping. The third American was freed in the rescue effort. The US military has had about 500 soldiers stationed in Mindanao since early 2002 to train local troops in how to combat the Abu Sayyaf. However the US soldiers are not allowed to have a combat role. * AFP