Mauritanian prosecutors Tuesday requested life sentences for four out of a total 11 defendants accused of abducting three Spanish aid workers in November 2009 as they went on trial in Nouakchott, dpa reported.
Six defendants were present, while the other five were being tried in absentia in the north-west African desert country.
The two Spanish men and a woman were abducted at gunpoint from a convoy of their aid organization as it was returning to the capital, Nouakchott, from the port city of Nouadhibou on November 29. The hostages were then taken to northern Mali.
The woman was released in March. The Spanish government is carrying out intense diplomatic efforts seeking to obtain the release of the two men.
The accused arrived in a white police bus at a Nouakchott criminal court, which also deals with terrorism cases, amid heavy security. Police prevented journalists from filming in the court room.
Defendants who were present in the court room included Malian Omar Ould Sidi Ould Hamma, known as Omar the Saharan. The 57-year-old is suspected of masterminding the kidnapping and of handing the hostages over against payment to Algerian Mokhtar Belmokhtar, who is believed to head al-Qaeda in the Sahara region.
Ould Hamma was captured by Mauritanian security and intelligence services in the Malian desert in February.
The Malian told the court he had not been involved in the abduction of the Spaniards. However, he admitted receiving from outsiders at the site of the kidnapping food, clothes and fuel for his four-wheel drive vehicle, which was allegedly used to transport the hostages.
Prosecution requested life imprisonment for Ould Hamma on charges of life-threatening attack, terrorism, abduction and illegal confinement.
Prosecutors also sought life sentences for a Mauritanian and an Algerian man, as well as for a man from Western Sahara, which Morocco regards as a part of its territory. Sentences of up to three years were proposed for a Mauritanian woman and man on charges of helping Ould Hamma.
The other accused were tried in absentia. They included Belmokhtar, who has been sentenced to death in his country, as well as people from Mali and Western Sahara.
Mauritanian prisons currently hold more than 60 suspected Islamist terrorists. About 20 of them have been tried and found guilty of terrorism charges.
Al-Qaeda earlier said it had abducted the Spaniards because of Spain's participation in international military operations in Iraq and Afghanistan.
It said it decided to release the woman for health reasons and because she converted to Islam. The Spanish government has denied paying a ransom for her.
The kidnappers were believed to be seeking a ransom for the two men, as well as the release of Islamist prisoners in Mauritania.