Four policemen were killed and one was wounded early Sunday morning when militants launched an attack on a police checkpoint in Yemen's southeastern province of Hadramout, a government official told Xinhua. "Unknown attackers raided a checkpoint of the special police forces located on the airport road in Seiyun town, in Hadramout province. As a result of the attack, four police members were killed and one was wounded," the local government official said on condition of anonymity. He said the gunmen fled the area shortly after the attack, and an investigation was underway. An intelligence source told Xinhua that the armed attack took place while a number of security chiefs were meeting in Seiyun to discuss the security situation in the region. Earlier in the day, three army personnel were injured when their military vehicle was hit by an improvised explosive device in Hadramout province, according to army sources. No group has so far claimed responsibility for the attack, but militants of the Yemen-based al-Qaida offshoot are usually blamed for such attacks, mostly in the country's southern regions. The al-Qaida in the Arabian Peninsula, which emerged in January 2009, is considered as the most strategic threat to the Yemeni government and its neighboring oil-rich Saudi Arabia.