Police in Spain on Monday arrested four Catholic priests accused of sexually abusing children in the southern city of Granada, the interior minister said.

The arrests came a week after a 24-year-old man there wrote to the Vatican alleging a group of priests molested him as a boy as well as other children.

A Colombian father was arrested Friday on suspicion of forcing his 11-year-old daughter to swallow 104 cocaine-filled capsules and trying to use her as a drugs mule.

On the run since the girl was hospitalized last week, Diego Fernando Mancilla Aguilar was sought on charges of attempted murder, using a minor to commit a crime and for drug trafficking, prosecutors said.

Spain is fighting a new wave of "homegrown" Islamic extremism, raiding cells and hunting radicals on the internet as scores of Spaniards join Islamist fighters in Syria and Iraq.

Ten years after al-Qaida-inspired bombings on Madrid commuter trains killed 191 people in March 2004, Spanish authorities are tackling a new wave of extremists.

Spain's eccentric Duchess of Alba, one of the nation's richest women who has more titles than any other aristocrat on earth, died on Thursday at the age of 88, a spokesman for her family said.

Maria del Rosario Cayetana Fitz-James Stuart passed away at her Duenas Palace in the southern city of Seville on Thursday morning, a family spokesman told AFP.

Spanish prosecutors said Tuesday they will sue Catalan president Artur Mas after he went ahead with a symbolic independence referendum in defiance of a court injunction.

"The public prosecutor's office will take the appropriate legal actions in the High Court of Justice of Catalonia," the public prosecutor's office said in a statement.

Spanish lawmakers adopted a motion Tuesday calling on the government to recognize a Palestinian state, following similar moves in other European nations.

The motion submitted by the opposition Socialists asks the conservative government to recognize Palestine in coordination with any similar move by the European Union.

Spain's parliament will vote Tuesday on a non-binding motion calling on the conservative government to recognize a Palestinian state in coordination with any similar EU move, parliamentary sources said.

The ruling Popular Party and the main opposition Socialists were in talks on the final wording of the motion which has the support of the government, sources from the two parties said.

Spain is seeing an unprecedented surge in home-grown Islamist extremism with more young Spanish Muslims than ever detained for links to terrorist groups in Syria, experts warned on Monday.

Top experts on Islamist radicalism from Spain's Royal Elcano international studies institute said the number of native Spaniards arrested on suspicion of terrorism offenses had surged since the beginning of the civil war in Syria in 2011 and the ongoing violence in Iraq.

Spanish authorities seized nearly one tonne of cocaine from a yacht off the Canary Islands in the Atlantic and arrested its three crew members, the interior ministry said Monday.

A Spanish customs ship intercepted the yacht, the "Liberty Belle", on Sunday some 200 nautical miles (370 kilometres) south of the Spanish holiday island of Gran Canaria, it said in a statement.

Several thousand people demonstrated in Madrid on Sunday in support of independence for the disputed territory of Western Sahara, a former Spanish colony in northwestern Africa.

About 3,000 protesters marched from Atocha railway station to the central Plaza de la Provincia behind a banner declaring "Sahara Free now!", an Agence France-Presse photographer said.