The weapons used to strike two Saudi oil plants were provided by the kingdom's arch-foe Iran, the Riyadh-led coalition fighting in Yemen said on Monday.
"The investigation is continuing and all indications are that weapons used in both attacks came from Iran," coalition spokesman Turki al-Maliki told reporters in Riyadh, adding they were now probing "from where they were fired".
The Tehran-backed Huthi rebels in Yemen, where a coalition is bogged down in a five-year war, claimed Saturday's strikes on two facilities owned by state energy giant Aramco which sent shock waves across oil markets.
But US Secretary of State Mike Pompeo has pointed the finger squarely at Tehran, saying there was no evidence the "unprecedented attack on the world's energy supply" was launched from Yemen.
"This strike didn't come from Yemen territory as the Huthi militia are pretending," Maliki said, adding that an investigation was ongoing into the attacks and their origins.
He labelled the Huthis "a tool in the hands of the Iranian Revolutionary Guards and the terrorist regime of Iran".
Trump has raised the possibility of military retaliation after the strikes, saying Sunday that Washington was "locked and loaded" to respond.
Oil prices rocketed on Monday after the strikes on Abqaiq, the world's largest oil processing facility, and the Khurais oil field in eastern Saudi Arabia knocked out nearly half of the top crude exporter's production.
