Saudi Arabia launched military strikes against Yemen’s defense ministry in the capital city of Sana’a in the latest escalation in the conflict between the two Arab nations, witnesses told the French news agency AFP.

It wasn’t immediately clear if the attacks were air or missile strikes, but they came following reports that Iran had manufactured the ballistic missile fired by Yemen’s Shiite rebels toward the Saudi capital a week ago.

Remnants of the missile bore “Iranian markings,” the top US Air Force official in the Mideast said Friday, backing the kingdom’s earlier allegations.

Saudi Arabia long has accused Iran of giving weapons to the Shiite rebels known as Houthis and their allies, though Tehran has just as long denied supplying them.

Saudi Arabia says it shot down the missile Nov. 4 near Riyadh’s international airport, the deepest yet to reach into the kingdom.

Saudi Arabia’s Foreign Ministry later said investigators examining the remains of the rocket found evidence proving “the role of Iranian regime in manufacturing them.”