The Navy retaliated for missiles fired at its ships off the coast of Yemen in recent days by destroying three radar sites in rebel-held territory, the Pentagon announced late Wednesday.

The Navy's counter attack with multiple Tomahawk land-attack cruise missiles was approved byPresident Obama.

"The United States will respond to any further threat to our ships and commercial traffic, as appropriate, and will continue to maintain our freedom of navigation in the Red Sea, the Bab al-Mandeb, and elsewhere around the world," Pentagon press secretary Peter Cook said in a statement.

The sites appear to have been destroyed, Cook said.

The Tomahawks were fired from the USS Nitze at about 4 a.m. local time, the Pentagon said.

Radar at the sites was active during the launches of cruise missiles at US ships, including the destroyer USS Mason on Wednesday, the Pentagon said. None of the enemy missiles damaged navy ships.

The radar sites were in remote areas and there was was little risk of civilian casualties, the Pentagon said.

The sites of the radar stations were near Ras Isa, norther of Mukha and near Khoka, all in Yeman.