Hundreds of migrants are swimming from Morocco to the tiny Spanish territory of Ceuta at the country’s northern tip, overwhelming border security, local authorities said Wednesday. While good weather usually brings a surge in migrant crossings by sea in the summer, Ceuta authorities said the current number of swimmers is unusual. “In the last few days, more than 1,500 migrants, including adults and minors, have reached Ceuta by sea,” the leader of Ceuta’s government, Juan Jesús Vivas, told journalists. Interior Minister Fernando Grande-Marlaska, in an interview with Spanish television channel laSexta, acknowledged authorities were facing “an extraordinary, exceptional situation.” It was not clear what prompted so many migrants to swim to Ceuta.