Spanish Defense Minister Carne Chacon confirmed Monday that two Spanish F-18 jet fighters have returned from their first mission in support of the recent UN resolution on Libya.

The two fighters, out of four that Spain has contributed to the NATO operation to enforce the no-fly zone and protect the civilian population in Libya, took off and returned from the Island of Sardinia.

They took off around midday local time armed with air to air missiles to patrol Libyan airspace and with the authorization to use their weapons if they met with any hostile aircraft. However, they returned without any incidents in their patrol.

A Spanish Boeing refueling aircraft also took to the skies Monday and returned to the Sardinian base.

Chacon added that submarine Tramontana and frigate Mendez Nunez have also set sail en-route to the operation zone.

The Mendez Munez sailed from the port of Ferrol and will arrive at the base of Rota in the south of Spain on Tuesday in order to be prepared to join any embargo operation. Meanwhile, the submarine sailed from Murcia in the south east of Spain and will take up a position off the coast of Libya.

On Tuesday, Spanish Prime Minister Jose Luis Zapatero will explain the operations to the Spanish Congress. The Congress will then hold a vote on Spain's participation in the allied military operation.

The secretary of the Organization of Zapatero's Socialist ( PSOE) party, Marcelino Iglesias, said Monday that Zapatero would ask Congress for permission for a military operation that would, " last for several weeks."