Spain sent 55 migrants back to Morocco on Monday a day after they forced their way into the Spanish territory of Melilla during an assault on the border in which two migrants died and 19 were injured.A total of 208 migrants entered Melilla on Sunday after climbing over two barbed wire fences which separate the tiny territory from northern Morocco.Madrid has "readmitted 55 people" who entered Melilla to Morocco, the Spanish central government's representative in the territory said in a statement.Another 140 migrants have requested asylum, 10 are recovering from their injuries and three are minors, it said.Spain has become the main entry point for migrants and asylum-seekers looking for a better life in Europe as other EU countries tighten up controls at their borders. A smuggling route through Libya to Italy has also been complicated by conflict and violence there.One man who took part in the mass storming of the border died shortly after he entered Melilla of a suspected heart attack."The preliminary results of the autopsy indicate there is no external injury which caused his death," the statement said.Another migrant died on the Moroccan side of the border in the attempt to cross over to Melilla. Moroccan authorities arrested 141 people as they tried to cross.Several Spanish Catholic associations which aid migrants issued a joint statement condemning the quick expulsion of the migrants from Melilla."Speed is not always a symptom of efficiency when what is at stake is people's lives and future," it said.Melilla, together with a second Spanish enclave, Ceuta, have the European Union's only land borders with Africa.Over 47,000 migrants have made it north to Spain since the start of the year, including about 5,000 by land, according to the International Organisation for Migration.An increasing number of Moroccans are attempting to reach Europe, either by taking the perilous sea route or via the Spanish enclaves of Ceuta and Melilla, which border Morocco.Morocco, which many Africans can visit without visas, has become a major gateway for sub-Saharan migrants into Europe.Moroccan authorities say they have stopped some 54 000 attempts by migrants to cross into Spain this year.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.