Saudi Arabia says it has killed "dozens" of Yemeni Shi'ite rebels who were carrying out a large-scale cross-border attack on the kingdom.
In a statement, Riyadh's Defense Ministry said three Saudi soldiers were killed in the late Thursday fighting in southern Najran province.
Najran province, Saudi Arabia
The ministry says the rebels attacked border posts and control points. They were repelled by a combination of Saudi ground troops and airstrikes.
It is believed to be the largest cross-border attack by the rebels since a Saudi-led coalition began a campaign of airstrikes against them five weeks ago.
Riyadh last week announced it was scaling back the air raids, saying it has accomplished its goal of weakening the rebels, which are believed to be backed by Iran.
The Houthis are loyal to former longtime President Ali Abdullah Saleh, who was ousted in 2012 during the so-called Arab Spring protests that swept the region.
The rebels have overtaken the Yemeni capital, Sana'a, and forced the country's Western-backed leader, Abdu Rabu Mansour Hadi, to flee to Saudi Arabia.
The fighting between various Yemeni groups, as well as the airstrikes, has helped create a humanitarian crisis in what was already the Arab world's poorest country.
Attempts by international relief groups to deliver humanitarian aid, including fuel and other commercial goods, has been severely hampered by the fighting.
U.N. chief Ban Ki-moon warned Thursday "humanitarian operations will end within days unless fuel supplies are restored." Ban also reiterated his call for an immediate cease-fire, or at least a pause, in the fighting.
The U.N. says at least 1,200 people have been killed. It estimates that around half of those killed were civilians.