The United States on Wednesday bombed three radar sites controlled by Houthi rebels in Yemen, the first direct US strike against the group following missile attacks against US warships last week, the Pentagon said in a statement.

The strikes in Houthi-controlled territory on Yemen's Red Sea coast, authorized by President Barack Obama, were conducted with Tomahawk cruise missiles fired by the destroyer USS Nitze, a US official said.

"Initial assessments show the sites were destroyed," the Pentagon said.