Yemeni security authorities captured three terrorists linked to the Yemen-based Al-Qaeda offshoot in the main southern port city of Aden on Monday, a government official told Xinhua.

"Troops of the anti-terrorism unit managed to arrest three Al- Qaeda militants who were planing to carry out armed attacks against government facilities in Aden to avenge the killing some of their comrades by a recent air strike," the local government official said on condition of anonymity.

The three terrorists were arrested as "they were trying to plant an improvised explosive device near the local council headquarters in Aden's neighborhood of Mansoura," the government source said.

Earlier on Monday, two roadside bombs simultaneously hit two buses belonging to Yemen's air forces near an air base in the capital Sanaa, but no casualties were reported.

Yemeni security services have blamed militants of the Yemen- based Al-Qaeda offshoot for a series of assassination attacks, mostly in the southern regions.

The Yemen-based Al-Qaeda in the Arabian Peninsula, which emerged in January 2009, is considered the most strategic threat to the Yemeni government and its neighboring oil-rich Saudi Arabia.