European leaders of all stripes are tense at the prospect of a second invasion into Ceuta as Morocco tightens security amid online campaigns to rally another mob across the border.

Social media posts calling for Moroccan citizens to launch another mass invasion of the Spanish territory are percolating across the internet. Spanish Defense Minister Margarita Robles warns that the border remains closed and any such attempts will be repelled. But that assurance has done little to assuage panic in the European Union that Spain will be the entry point for a flood of migrants.