barriersImmigrants Rush the Spanish Border (PHOTOS)05.30.14barriersImmigrants Rush the Spanish Border (PHOTOS)Six men have been arrested on terror charges in Spain's north African enclave of Melilla. Earlier in the week, about 400 migrants breached the border fence. See photos.05.30.14 3:13 PM ETJesus Blasco de Avellaneda/ReutersSpain's interior ministry said on Friday that it has arrested six men on terror charges in its north African enclave of Melilla. The men, including one described as the "first Spanish jihadist" to return from Mali, are suspected of recruiting fighters for militant groups in Libya and Mali. Earlier in the week, about 400 migrants breached the 19-foot-tall fence between Melilla and Morocco, likely seeking work or asylum. Melillia is the only land border between the European Union and Africa. Here, see photos from recent border breaches. Jesus Blasco de Avellaneda/ReutersAfrican migrants sit on top of a border fence between Morocco and Melilla during an attempt to cross into Spanish territory in April. Spain has more than doubled the strength of security forces at Melilla, after recent weeks have brought the biggest border rushes in years. Immigrants from all over Africa regularly dare the razor-wire fences of Spanish enclaves Ceuta and Melilla, which are surrounded by Moroccan territory and sea. Alexander Koerner/GettySyrian refugees leave the Centre for Temporary Stay of Immigrants to make their way to the ferry terminal in Melilla, where they will board a cruise ship bound for Malaga on the Spanish mainland. During the morning hours, around 70 Sub-Saharan migrants tried to climb the fence into Melilla, where one had to be treated by paramedics. Jesus Blasco de Avellaneda/ReutersAn African migrant is lowered down from a border fence by a Spanish Civil Guard as fellow migrants assist. Spain has more than doubled the strength of security forces at Melilla, after about 500 people stormed its fences in the biggest border rush in years. Jesus Blasco de Avellaneda/ReutersAround 400 people stormed the border and at least 150 of them reached European territory, according to local authorities. Santi Palacios/APSpanish Civil Guard officers stand by as a Sub-Saharan migrant sits on top of a pole set in a metallic fence that divides Morocco and Melilla. During the pre-dawn border storming Wednesday, cries of pain and noises of people being hit could be heard as police from both sides tried to prevent dozens of the migrants from entering the city from Morocco. Blasco de Avellaneda/ReutersPolice officers detain a would-be immigrant at a border fence, following a morning assault on the border in an attempt to cross into Spain. Jesus Blasco de Avellaneda/ReutersAfrican migrants climb a border fence covered in razor wire. Jesus Blasco de Avellaneda/AFP/GettySpanish police officers arrive to prevent would-be immigrants from crossing a border fence. Blasco de Avellaneda/AFP/GettyWould-be immigrants stand atop a border fence. Jesus Blasco de Avellaneda/ReutersA Spanish Civil Guard approaches African migrants sitting on top of a border fence. Alexander Koerner/AFP/GettyA general view of the fence ending in the sea at the border between Morocco and Melilla. Santi Palacios/APSub-Saharan migrants scale a metallic fence, early in the morning on May 28.