An F-100 frigate, an S-74 submarine and a CN-235 maritime surveillance plane will also be deployed to help enforce an arms embargo on Libya, once parliamentary approval has been received, it said in a statement late Saturday.

Details of Spain's involvement were announced at a news conference in Paris earlier Saturday by Prime Minister Jose Luis Rodriguez Zapatero following the international summit on Libya that discussed the intervention.

The United States, Britain and France later pounded targets in Libya with air strikes and Tomahawk missiles at the start of the campaign to prevent Moamer Qadhafi from crushing a month-old uprising against his rule.

Spanish Defence Minister Carme Chacon chaired a meeting of senior military and defence chiefs in Madrid late Saturday to coordinate the country's participation in the operation, the ministry statement said.

It said the four Spanish F-18s and the Boeing refuelling plane had arrived in the Italian base of Decimomannu on the island of Sardinia.

"These planes will carry out patrol missions and will be operational from tomorrow, Sunday," it said.

It said around 500 Spanish troops would eventually be involved.

Spain had already announced on Friday it would allow NATO to use two military bases, at Rota and at Moron de la Frontera in the south of the country, for the operation over Libya.

The UN Security Council late Thursday passed a resolution approving "all necessary measures" to impose a no-fly zone in Libya, protect civilian areas and pressure Qadhafi into accepting a ceasefire.

The Security Council last month also ordered an arms embargo against Libya and other sanctions against Qadhafi's family.