At least six security members were seriously injured Saturday morning in a bomb attack targeted a police headquarters in Yemen\'s southern port city of Aden, a police officer told Xinhua. The local police officer said on condition of anonymity that three bombs detonated at the main gate of a police station headquarters in Khor Maksar district, seriously injuring at least six security members. \"Unidentified people threw grenade bombs on the soldiers guarding the police station, causing serious injuries among them,\" he said, adding that \"heavy clashes took place after the explosion. \" Saturday\'s attack came just one day after the head of counter- terrorism force in Aden was killed when a car bomb exploded beneath his vehicle near the Aden\'s International Airport. A number of intelligence offices and police stations in Aden have repeatedly been the targets in the last several months. The government authorities usually accuse militants of the al- Qaida in the Arabian Peninsula (AQAP) of being behind these attacks. In nearby Abyan province, hundreds of AQAP militants captured the provincial city and at least three towns late in May.