Saudi Arabia said Wednesday that attacks on two of its oil tankers and a major pipeline targeted not only its own security but that of the world's supplies.

Drone attacks claimed by Iran-aligned Yemeni rebels shut down one of the kingdom's main oil pipelines on Tuesday, further ratcheting up Gulf tensions after the mysterious sabotage of four ships, two of them Saudi tankers, just outside the Gulf on Sunday.

With international pressure growing for a political solution to Syria's war, opposition groups appear to have resigned themselves to the idea that Bashar Assad cannot be removed by force.

Syrian political and armed opposition factions agreed Thursday at unprecedented talks in Riyadh to negotiate with Assad, but insisted he must step down before any political transition begins.

Saudi police killed two suspected militants and arrested three others during raids to foil an "imminent terrorist operation," the interior ministry said Monday.

"This cell planned to carry out an imminent terrorist operation that had reached late stages of execution," the ministry said, without disclosing a target.

Loyalist forces in Yemen backed by a Saudi-led coalition killed at least 20 Iran-backed insurgents Saturday, the military said, as they pressed their offensive on the rebel-held capital Sanaa.

Twelve other rebels were captured in the operation launched on the northwestern edge of Marib province, a key battleground in the fight for control of the capital, said a military official

Saudi Arabia's top religious leader says a stampede which killed 717 pilgrims was beyond human control, official media reported on Saturday, the final day of this year's hajj.

The stampede was the worst disaster in a quarter-century to strike the annual event and drew fierce criticism of the Saudi authorities' handling of safety, particularly from regional rival Iran.

Air raids by Saudi-led coalition warplanes killed 15 people in Yemen's capital in one of the heaviest nights of bombardment in months, aid workers and witnesses said Saturday.

One rescuer told AFP at least 10 civilians were among the dead.

Saudi Ambassador to Lebanon Ali Awadh Asiri has said that the recent travel warning issued for Lebanon came out of Riyadh's keenness on the safety of its citizens.

Asiri told pan-Arab daily al-Hayat published on Thursday that Saudi Arabia fears its citizens could be harmed in the latest events that shook the country.

A Saudi border guard has been killed by rocket fire from anti-government rebels in northern Yemen, Riyadh's official SPA news agency said on Sunday.

A border post in the kingdom's Jazan region came under attack on Saturday, prompting guards to respond to the fire, the SPA said, quoting an interior ministry spokesman. 

The leader of Yemen's Iran-backed rebels said a political settlement with the exiled government was still possible after what he called the "short-term" setback of their ouster from second city Aden.

Abdulmalik al-Huthi said the rebels would welcome a new attempt by a third party to broker a deal after the failure of U.N.-brokered peace talks in Geneva in June. 

Prime Minister Tammam Salam has stressed that he will not resign despite growing political and environmental crises that are threatening to spiral out of control.

According to the Kuwaiti al-Anbaa daily published on Thursday, Salam told religious officials and diplomats that the country's political situation is grave but that he would not announce his resignation.