The European Union announced details Tuesday of its planned anti-piracy patrols off Somalia's coast, saying at least four warships backed by aircraft would begin policing the dangerous waters in December.

The EU flotilla will eventually take over patrolling the area from NATO ships, which arrived over the weekend and began escorting vessels on Monday.

An EU official said the bloc's new flotilla would include four to six ships backed by three or four maritime patrol aircraft, and would be led by British Vice Admiral Philip Jones. The official spoke on condition of anonymity as he was not authorized to be quoted by media. Two other EU officials corroborated the details, also on condition of anonymity.

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The EU had announced its planned patrols last month to help guard the waters off Somalia, which are considered among the most dangerous amid a renewed outbreak in piracy.

Somalia — caught up in an Islamic insurgency — has no functioning government, no navy and no coast guard to police its coast, which includes the Gulf of Aden, one of the world's busiest shipping lanes.

Already 10 EU governments have volunteered ships or aircraft to the EU force, the EU official said.

Several non-European nations, including India, Malaysia and Singapore, have also expressed interest in joining the EU force, he said. Russia also said it would help.

Meanwhile, NATO sent three ships over the weekend into the Gulf of Aden for anti-piracy patrols and escorting cargo vessels. The Greek frigate HS Themistokles accompanied a World Food Program cargo vessel carrying aid to Somalia. The Italian destroyer ITS Durand de la Penne escorted a merchant vessel chartered by the African Union. And the British frigate HMS Cumberland has been assigned surveillance and deterrence activities, NATO said in a statement.

Several warships of the U.S. Navy's 5th Fleet have also been deployed off the Horn of Africa.

Four other NATO warships sailed over the weekend to ports in the Middle East. And the Russian missile frigate Neustrashimi is in the Yemeni port of Aden.

About 20,000 vessels pass annually through the Gulf of Aden, which links the Indian Ocean with the Suez Canal and the Mediterranean Sea.

While maritime piracy worldwide has declined over the past five years, piracy off Somalia has soared. The region has overtaken the Straits of Malacca — the waterway shared by Indonesia, Singapore and Malaysia — as the world's most pirate-infested region.