Thousands of people demonstrated Friday in Tehran to denounce Saudi-led air strikes on Shiite rebels in Yemen, where Iran is accused of meddling by Saudi Arabia.

The protests came as Iran rejected anew Saudi claims it was interfering in Yemen by backing the Huthi rebels, and accused Riyadh of seeking to absolve itself of responsibility in the war.

Iran rejected Friday allegations it was interfering in Yemen by backing Shiite rebels there, accusing Saudi Arabia of seeking to absolve itself of responsibility in the war-torn Arabian Peninsula country.

Riyadh's new Foreign Minister Adel al-Jubeir on Thursday criticized what he called Iran's "negative" role in the Yemen conflict, and repeated claims Tehran was providing arms and funding to anti-government forces.

Iran is a destabilizing force that must not be allowed to have a nuclear weapon, top U.S. diplomat John Kerry said in Saudi Arabia Thursday, aiming to calm Riyadh's worries.

Saudi Arabia and its Gulf neighbors fear Tehran might be able to develop an atomic bomb despite an international accord being drafted which aims to prevent that.

Saudi Arabia wants to bring together the many branches of war-torn Syria's armed and political opposition to discuss what to do after the regime's downfall, opposition sources said Thursday.

The Sunni-ruled kingdom of Saudi Arabia is a main backer of forces fighting to topple Syria's President Bashar Assad, while its Shiite-dominated rival Iran backs him.

Saudi Arabia on Thursday proposed a five-day humanitarian ceasefire in Yemen after weeks of air strikes and clashes, with top U.S. diplomat John Kerry urging Iran-backed rebels to accept the offer.

The bombing by a Saudi-led coalition has failed to halt an advance by the Shiite Huthi rebels in Yemen, and concern has been mounting over increasing civilian deaths.

An Apache helicopter gunship from the Saudi-led coalition fighting Yemeni rebels made an emergency landing Thursday just inside the border from Yemen, a Saudi official said, ruling out hostile fire.

"The pilots are safe," but there was some damage, said the source, asking for anonymity.

Progressive Socialist Party chief MP Walid Jumblat dismissed claims on Thursday that former Prime Minister Rafik Hariri's Feb. 14, 2005 assassination was linked to rampant corruption in Lebanon or a rising Saudi influence in the country.

“Hariri was killed for political reasons,” Jumblat told the Special Tribunal for Lebanon during the Defense Counsel's cross-examination.

Top U.S. diplomat John Kerry was in Saudi Arabia Thursday to push for a "pause" in air strikes in Yemen while the country's exiled authorities urged a foreign ground offensive against rebels.

Weeks of air strikes by a Saudi-led coalition have failed to halt an advance by the Iran-backed Shiite Huthi rebels in Yemen and concern has been mounting over increasing civilian deaths and a growing humanitarian crisis.

With Iran emboldened and the United States seen in retreat, President Barack Obama faces the vexed task of restoring lost trust and influence when he hosts Gulf leaders at Camp David next week.

It is a meeting that Gulf officials privately describe as "a welcome gesture," "thrown together" and "long overdue."

Shells fired from Yemen killed five people in Saudi Arabia on Wednesday in a second day of cross-border bombing blamed on Shiite Huthi rebels, civil defense authorities said.

Two civilians in a car and two passers-by were killed by a shell in the city of Najran, while 11 others were wounded, the civil defense department said in a statement carried by the SPA state news agency.