Just two days after reports indicated that Yemen’s Iran-backed Houthi rebels were prepared to participate in UN-brokered peace talks with Abd Rabbuh Mansur Hadi’s government in exile, clashes on the Saudi border have intensified.

On Friday, the Saudi press agency said it had used Apache helicopters and artillery to repel a Houthi-led advance, killing “dozens” of militants. Four Saudis were also killed.

Meanwhile, Riyadh stepped up airstrikes around the Yemeni capital targeting what the Saudis say were arms depots. The Houthis, however, say the aerial bombardment is inflicting untold civilian casualties, mostly women and children. Here's Reuters:

Coalition Arab bombings killed around 58 people across Yemen on Wednesday and Thursday, the state news agency Saba, controlled by the Houthis, said. 48 people, most of them women and children, were killed in air strikes on their houses in the Houthi heartland in the rural far north adjoining Saudi Arabia. The reports could not be independently verified.

On Saturday, Riyadh claimed the Houthis, in concert with forces loyal to former President Ali Abdullah Saleh, fired a scud missile at Saudi Arabia for the first time.

The scud, which apparently targeted the city of Khamis Mushait in southwest Saudi Arabia, was intercepted by two Patriot missiles. “At 2:45am on Saturday morning, the Houthi militias and ousted [president] Ali Abdullah Saleh launched a Scud missile in the direction of Khamees al-Mushait, and praise be to God, the Royal Saudi air defences blocked it with a Patriot missile," a statement said.

Khamis Mushait is home to the US-desiged and constructed King Khalid Air Force base, from which airstrikes on Houthi positions have been launched throughout the conflict.

(King Khalid Air Force Base)

Friday’s attack by Abdullah Saleh’s Republican Guard and the Houthis in the Jizan province was billed as the largest “offensive” mounted by the rebels since the onset of hostilities months ago. The fighting reportedly began when rebels fired rockets at Saudi positions and promptly ended when the Saudi army called in air support from Apache gunships.

(a rebel fires on Saudi positions near the border)

Note that this latest escalation comes a month and a half after Saudi Arabia declared a George Bush-style "mission accomplished"-type end to operation Decisive Storm, claiming the 'coalition' airstrikes had "successfully eliminated the threat to the security of Saudi Arabia."

The declaration looks to have been a bit premature.

The Houthis are scheduled to attend peace talks in Geneva on June 14. That is unless the Saudis launch a ground invasion in the interim.