U.N. Yemen envoy says 'not entirely clear' who is behind Saudi oil attack

United Nations Yemen envoy Martin Griffiths told the U.N. Security Council on Monday that it was "not entirely clear" who was behind Saturday's attack on Saudi oil facilities but he said it had increased the chances of a regional conflict.

"It's not entirely clear who was behind the attack, but the fact that Ansar Allah has claimed responsibility is bad enough," Griffiths told the council, using the official name of Yemen's Houthi group. "This extremely serious incident makes the chances of a regional conflict that much higher."