Police arrested two suspected jihadists Tuesday in Spain's north African territory of Ceuta on charges of belonging to a group that was "prepared" to launch an attack on Spanish soil, the government said.

"The national police at dawn this morning carried out an anti-terrorist operation which led to the detention in Ceuta of two suspected jihadists," the interior ministry said in a statement.

Spanish police on Saturday arrested four suspected Islamist extremists who it said were prepared to launch attacks in Spain, the government said.

Officers detained two pairs of brothers, Spaniards of Moroccan origin, in the Spanish territory of Ceuta bordering Morocco, the interior ministry said in a statement.

Aisha has lived all her life in one neighborhood in Spain's African territory of Ceuta, but now she is willing to move -- even to the war zone of Syria.

"I would go and live with my family in the Islamic State in Syria, and if my husband died there in combat, I would accept it," said the mother-of-four, dressed in a black hijab, who asked for her real name to be concealed.

Some 350 African migrants tried to storm a fence from Morocco into Spanish territory on Wednesday, authorities said, the latest in a wave of desperate arrivals at Europe's southern border.

Just three of the migrants who charged towards the seven-meter (23-foot) fence in separate locations at dawn made it into the territory of Melilla, the Spanish government delegation there said in a statement.

The U.N. on Tuesday warned Spain over plans to instantly deport migrants who clamber over the border fence into its north African territories, saying Madrid could end up breaking international law.

"UNHCR is concerned over a proposal by Spain to legalize automatic returns of people trying to cross border fences into its enclaves of Ceuta and Melilla," said the U.N. refugee agency's spokesman William Spindler.

Security forces averted an attempt by about 1,000 migrants to rush a towering, triple-layer border fence separating Morocco from the Spanish-held north African territory of Melilla, Spain's government said Tuesday.

Authorities say it was the latest bid by desperate migrants to enter the Spanish cities of Melilla and Ceuta by scrambling over the six-meter (19-foot) border fences or crossing the Mediterranean in flimsy vessels.