Not all Muslim invaders were simply raiders. There were also resistance movements fighting against the Allied invaders. The inhabitants of Spain were summoned for fighting against the French invaders. This defeat left Syria vulnerable to the Muslim invaders. The Pelusium fortress served as means of protection from invaders coming towards the Nile Delta. Castles needed to be fortified to withstand assaults from invaders. These were modified, expanded, and elaborated by the Ionian Greek invaders and colonists. Neither the Invaders nor their planet were ever named. The sweltering heat soon felled many of the northern European invaders. The ants are ranked among the world's 100 worst animal invaders. "Kuta" were notably used by Muslims for defense against foreign invaders. During the early Byzantine period it served as a place of refuge against foreign invaders. Zia's international standing greatly rose after his declaration to fight the Soviet invaders. They're like waves of Space Invaders. The resultant game borrows elements from "Asteroids" and "Space Invaders".