ADEN, Yemen, June 15 (Xinhua) -- A total of nine people were killed, and ten others were wounded when a group of unidentified gunmen fired at an army bus on Sunday in Yemen's southern port city of Aden, according to a government official.
"Masked armed men ambushed a military bus of the armed forces in Aden's neighborhood of Sheikh Othman...which led to the killing of nine people including high-ranking officers," the local government official said on condition of anonymity.
Some of the wounded were suffering from sever injuries, he said.
"The bus carrying military and medical officers was targeted while traveling in a main street and heading toward the Basuhib military hospital in Aden province," the government source added.
However, the identities of the armed militants remained unclear.
Special security forces are now being deployed at the scene of the attack, and sealed the area, according to the Yemeni official, adding that an investigation has been underway.
A military intelligence official in Aden said police are hunting the perpetrators but no arrests have been made. The local government has vowed to bring culprits to justice.
Currently, no group has stepped forward to take the responsibility, but local military officials said they have thwarted several plots by militants with the Yemen-based al-Qaida splinter group over recent months.
The Yemeni military and security forces, with support from the United States, have recently intensified operations against suspected al-Qaida strongholds throughout the country, killing many non-Yemeni al-Qaida suspects.
Al-Qaida in the Arabian Peninsula, also known as AQAP, is considered a major threat to the Yemeni government and neighboring oil-rich Saudi Arabia.
The al-Qaida cell has vowed to hit back in Yemen' s main cities, including the capital Sanaa, after it was driven out of its key bastions of Shabwa and Abyan last month.
The terror network's militants have retaliated by launching suicide car-bombs and roadside bombings across the impoverished Arab country.
Besides its turf war against the al-Qaida militants, the Yemeni government also faces a threat posed by southern separatists for independence, as well as clashes with the Shi'ite Muslim Houthi movement.