RIYADH, Sept 18 (Reuters)

Saudi Arabia displayed remnants of what it described as Iranian drones and cruise missiles used in an attack on Saudi oil facilities as "undeniable" evidence of Iranian aggression.

Defence Ministry spokesman Colonel Turki al-Malki said a total of 25 drones and missiles were launched at two oil plants in last weekend's strikes, including what he identified as Iranian Delta Wing unmanned aerial vehicles (UAV) and "Ya Ali" cruise missiles. He said the missiles have been used by Iran's Revolutionary Guards.

"The attack was launched from the north and unquestionably sponsored by Iran," he told a news conference. "The evidence ... that you have seen in front of you, makes this undeniable.”

Iran has denied any involvement in the assault that initially halved Saudi Arabia's oil production.

Malki said both drones and missiles were launched at Abqaiq, home to the world's largest oil processing facility, and that cruise missiles had targeted Khurais.

Yemen's Iran-aligned Houthi movement, which has been battling a Saudi-led military coalition, had claimed responsibility for the strikes.

Malki, who is also the spokesman for the coalition, reiterated that the attack could not have come from Yemen, saying the Houthi movement was "covering up" for Iran.

(Reporting by Maher Chmaytelli, Lisa Barrington and Tuqa Khaled in Dubai and Reuters team in Riyadh; Editing by Angus MacSwan and Howard Goller)