By Elwely Elwelly, Yomna Ehab and Muhammad Al Gebaly DUBAI/CAIRO, Sept 8 (Reuters) - Yemen's Tehran-backed Houthis attacked four cities in the south of U.S. ally Saudi Arabia on Tuesday, wounding more than 70 people and setting oil installations ablaze in what appeared to be a major expansion of the six-month-old Middle East war.

The Iran-backed Houthi rebels in Yemen said Wednesday that Saudi-backed forces had launched dozens of airstrikes overnight across four Yemeni provinces after rebel attacks on Saudi Arabia ignited fire...

The Houthis on Tuesday said they targeted Saudi energy sites belonging to oil giant Aramco in southern areas, with the group's military spokesperson calling it "a broad operation".

The Iran-backed Houthi rebels in Yemen said Wednesday that Saudi-backed forces had launched dozens of airstrikes overnight across four Yemeni provinces after rebel attacks on Saudi Arabia ignited fire...

The price of oil has surpassed $100 a barrel for the first time in almost six weeks after attacks on oil facilities and ships in the Middle East threatened to debilitate an already weakened supply cha