Saudi forces have reportedly repulsed a major attack launched by Shia Houthi rebels on their southern border, Saudi state media said.
An air campaign led by a Saudi-led coalition had targeted Houthi rebels in Yemen since late March, reported the BBC.
However, Thursday's attack, near the Saudi town of Najran, was the major assault on Saudi territory since air strikes began. Saudi reports said that "dozens" of rebels were killed.
As clashes continued, aid groups said that a lack of fuel was severely impeding their operations in Yemen.
The rebels, who control most of northern Yemen, including the capital Sanaa, have been battling government forces for months.
