WASHINGTON: US Defence Secretary Leon Panetta has signed orders to send Patriot missiles and 400 military personnel to Turkey to defend against rocket attacks from Syria, news media reported early Friday.

A total of six Patriot missile batteries will be sent to Turkey — two from the United States, two from Germany and two from the Netherlands, the New York Times reported.

All six batteries will be under Nato's command, the newspaper said, and all six are scheduled to be operational by the end of January.

The 20-month-old uprising against Syrian President Bashar al-Assad has turned increasingly bloody and heavy fighting has often erupted along Syria's northern border with Turkey, which is supporting the Syrian opposition.

The Patriot system is designed to intercept aircraft or missiles. Turkey has asked Nato to deploy Patriot missiles to shore up its 900-km (560-mile) border, where it fears security may crumble as the Syrian army fights harder to contain the rebels - who have enjoyed sanctuary in Turkey.