World Bulletin / News Desk

The US military directly targeted Yemen's Huthi rebels for the first time on Thursday, hitting radar sites controlled by the insurgents after US warships came under missile attacks twice in four days.

The United States is providing logistical support to a Saudi-led coalition that has been battling the rebels since last year, but Thursday's strikes marked the first time Washington has taken direct action against the Huthis.

The Pentagon said the cruise missile strikes -- authorised by President Barack Obama -- were launched at 4:00 am local time (0100 GMT) by the destroyer USS Nitze against territory on Yemen's Red Sea coast controlled by the Huthis.

"Initial assessments show the sites were destroyed," Pentagon Press Secretary Peter Cook said in a statement.

The strikes "targeted radar sites involved in the recent missile launches threatening USS Mason and other vessels operating in international waters in the Red Sea and the Bab al-Mandeb (Strait)," it added.

"These limited self-defence strikes were conducted to protect our personnel, our ships, and our freedom of navigation in this important maritime passageway."

The USS Mason, a destroyer, was targeted on Wednesday by a missile fired from rebel-held territory which crashed into the ocean before reaching its target.

The Mason and the USS Ponce, an amphibious staging base, were previously targeted on Sunday by two missiles that also fell short.

"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," Cook said.

A Yemeni military source said the US missiles hit radar sites near Al-Makha and Al-Khukha in southwestern Yemen and Ras Isa, further north along the coast.